Life Extension Magazine®

Food Sensitivities

Scientifically reviewed by: Dr. Gary Gonzalez, MD, in August 2023. Written by: Life Extension Editorial Staff.

Vitamin D and vascular calcification.

PURPOSE OF REVIEW: Vascular calcification is frequently found in patients with osteoporosis, atherosclerosis and chronic kidney disease, leading to high morbidity and mortality rates. The effects of vitamin D excess and deficiency on vascular calcification are reviewed in this article. RECENT FINDINGS: There is evidence from experimental studies that mediacalcinosis induced by vitamin D excess is an active and reversible process. Vitamin D excess, however, is rarely seen in the general human population. Experimental data also demonstrate that physiologic vitamin D actions include the inhibition of processes that are important for intimal and medial artery calcification such as pro-inflammatory cytokine release, adhesion molecule release, and proliferation and migration of vascular smooth muscle cells. In uremic rats, low levels of the vitamin D hormone calcitriol are associated with massive vascular and soft tissue calcifications. Whereas retrospective studies already indicate a beneficial effect of active vitamin D on mortality rates in chronic kidney disease, little is yet known about the effect of vitamin D deficiency on cardiovascular morbidity and mortality in the general population. SUMMARY: Available data indicate that vitamin D exerts a biphasic ‘dose response’ curve on vascular calcification with deleterious consequences not only of vitamin D excess but also of vitamin D deficiency.

Curr Opin Lipidol. 2007 Feb;18(1):41-6

25-hydroxyvitamin D levels inversely associate with risk factor developing coronary artery calcification.

Vitamin D deficiency associates with increased risk for cardiovascular events and mortality, but the mechanism driving this association is unknown. Here, we tested whether circulating 25-hydroxyvitamin D concentration associates with coronary artery calcification (CAC), a measure of coronary atherosclerosis, in the Multi-Ethnic Study of Atherosclerosis. We included 1,370 participants: 394 with and 976 without chronic kidney disease (estimated GFR <60 ml/min per 1.73 m(2)). At baseline, CAC was prevalent among 723 (53%) participants. Among participants free of CAC at baseline, 135 (21%) developed incident CAC during 3 yr of follow-up. Lower 25-hydroxyvitamin D concentration did not associate with prevalent CAC but did associate with increased risk for developing incident CAC, adjusting for age, gender, race/ethnicity, site, season, physical activity, smoking, body mass index, and kidney function. Further adjustment for BP, diabetes, C-reactive protein, and lipids did not alter this finding. The association of 25-hydroxyvitamin D with incident CAC seemed to be stronger among participants with lower estimated GFR. Circulating 1,25-dihydroxyvitamin D concentrations among participants with chronic kidney disease did not significantly associate with prevalent or incident CAC in adjusted models. In conclusion, lower 25-hydroxyvitamin D concentrations associate with increased risk for incident CAC. Accelerated development of atherosclerosis may underlie, in part, the increased cardiovascular risk associated with vitamin D deficiency.

J Am Soc Nephrol. 2009 Aug;20(8):1805-12

Vitamin D and cardiovascular disease.

Cardiovascular disease (CVD) is a major cause of morbidity and mortality worldwide. Recently vitamin D deficiency has been identified as a potential risk factor for many diseases not traditionally associated with vitamin D, such as cancer and CVD. This review discusses the evidence suggesting an association between low 25-hydroxyvitamin D levels and CVD and the possible mechanisms mediating it. Vitamin D deficiency has been associated with CVD risk factors such as hypertension and diabetes mellitus, with markers of subclinical atherosclerosis such as intima-media thickness and coronary calcification as well as with cardiovascular events such as myocardial infarction and stroke as well as congestive heart failure. It could be suggested that vitamin D deficiency contributes to the development of CVD through its association with risk factors, such as diabetes and hypertension. However, direct effects of vitamin D on the cardiovascular system may also be involved. Vitamin D receptors are expressed in a variety of tissues, including cardiomyocytes, vascular smooth muscle cells and endothelial cells and vitamin D has been shown to affect inflammation and cell proliferation and differentiation. While much evidence supports a potential antiatherosclerotic effect of vitamin D, prospective, placebo-controlled randomized as well as mechanistic studies are needed to confirm this association. Since vitamin D deficiency is easy to screen for and treat, the confirmation of such an association could have important implications for both, patient care and health policy.

Curr Vasc Pharmacol. 2009 Jul;7(3):414-22

Vitamin D receptor activators can protect against vascular calcification.

An apparent conflict exists between observational studies that suggest that vitamin D receptor (VDR) activators provide a survival advantage for patients with ESRD and other studies that suggest that they cause vascular calcification. In an effort to explain this discrepancy, we studied the effects of the VDR activators calcitriol and paricalcitol on aortic calcification in a mouse model of chronic kidney disease (CKD)-stimulated atherosclerotic cardiovascular mineralization. At dosages sufficient to correct secondary hyperparathyroidism, calcitriol and paricalcitol were protective against aortic calcification, but higher dosages stimulated aortic calcification. At protective dosages, the VDR activators reduced osteoblastic gene expression in the aorta, which is normally increased in CKD, perhaps explaining this inhibition of aortic calcification. Interpreting the results obtained using this model, however, is complicated by the adynamic bone disorder; both calcitriol and paricalcitol stimulated osteoblast surfaces and rates of bone formation. Therefore, the skeletal actions of the VDR activators may have contributed to their protection against aortic calcification. We conclude that low, clinically relevant dosages of calcitriol and paricalcitol may protect against CKD-stimulated vascular calcification.

J Am Soc Nephrol. 2008 Aug;19(8):1509-19

25-hydroxyvitamin D deficiency is independently associated with cardiovascular disease in the Third National Health and Nutrition Examination Survey.

OBJECTIVE: Serum 25-hydroxy-vitamin D [25(OH)D] levels are inversely associated with important cardiovascular disease (CVD) risk factors. However, the association between 25(OH)D levels and prevalent CVD has not been extensively examined in the general population. METHODS: We performed a cross-sectional analysis of data from the Third National Health and Nutrition Examination Survey (1988-1994) and examined the association between serum 25(OH)D levels and prevalence of CVD in a representative population-based sample of 16,603 men and women aged 18 years or older. Prevalence of CVD was defined as a composite measure inclusive of self-reported angina, myocardial infarction or stroke. RESULTS: In the whole population, there were 1308 (8%) subjects with self-reported CVD. Participants with CVD had a greater frequency of 25(OH)D deficiency [defined as serum 25(OH)D levels <20 ng/mL] than those without (29.3% vs. 21.4%; p<0.0001). After adjustment for age, gender, race/ethnicity, season of measurement, physical activity, body mass index, smoking status, hypertension, diabetes, elevated low-density lipoprotein cholesterol, hypertriglyceridemia, low high-density lipoprotein cholesterol, chronic kidney disease and vitamin D use, participants with 25(OH)D deficiency had an increased risk of prevalent CVD (odds ratio 1.20 [95% confidence interval (CI) 1.01-1.36; p=0.03]). CONCLUSIONS: These results indicate a strong and independent relationship of 25(OH)D deficiency with prevalent CVD in a large sample representative of the US adult population.

Atherosclerosis. 2009 Jul;205(1):255-60

The role of vitamin D in the development of cardiac failure.

Congestive heart failure is a chronic disease, whose incidence is especially growing in the subpopulation of elderly people. The majority of these patients have vitamin D levels in the insufficient range. Skin synthesis is the most important vitamin D source for humans. Congestive heart failure patients have relatively low outdoor activities. Consequently, a disease-related sedentary lifestyle is an important cause for the insufficient vitamin D status in patients. However, there is an accumulating body of evidence that vitamin D insufficiency plays a role in the etiology and pathogenesis of congestive heart failure. Vitamin D has direct effect on heart cells and indirect effect on the risk factors of the disease. Four major potential mechanisms may be important to explain the direct effects of vitamin D against congestive heart failure: the effect on myocardial contractile function, the regulation of natriuretic hormone secretion, the effect on extracellular matrix remodelling and the regulation of inflammation cytokines. It has been demonstrated that vitamin D has a high impact on congestive heart failure main risk factors as hypertension, renin-angiotensin system malfunction and atherosclerosis. In spite of the robust preclinical data only few clinical observations prove the positive effect of vitamin D on congestive heart failure.

Orv Hetil. 2009 Jul 26;150(30):1397-402

Vitamin K-controlled diet: problems and prospects.

Different natural (phylloquinone and menaquinone) and synthetic (menadione) compounds carry out the same action of vitamin K in the human body. Vitamin K is a substrate for the enzyme catalysing the posttranslational conversion of specific glutamyl residues to gamma-carboxyglutamyl residues in certain proteins connected with the coagulation (Factors II, VII, IX, X), the anticoagulation (Proteins C and S) and other organic functions (osteocalcin). Foods rich in vitamin K (1/4) and the action of gut bacteria (3/4) can give rise to changes in vitamin K status. Dietary factors, alterations of gut bacteria or/and troubles in the absorption of this vitamin can cause a lack, which at first interferes in the normal hemostatic function and later on it leads to modifications in the bone structure. Therefore, it is necessary to pay a lot of attention to dietary intake, adequacy, bioavailability, absorption and metabolism of vitamin K and compounds with an action similar to it for understanding the signs of lack, choosing the most suitable therapy and managing accurately the coumarin-based oral anticoagulants.

Clin Ter. 2005 Jan-Apr;156(1-2):41-6

Vitamin K in the Norwegian diet and osteoporosis.

BACKGROUND: In search of vitamin K literature, interesting results were discovered. A summary is presented. MATERIAL AND METHODS: The literature was found by using Medline. The level of vitamin K1 in the Norwegian diet was estimated from tables of food consumption and vitamin K1 per 100 g. RESULTS: Vitamin K is required for the carboxylation of the amino acid glutamic acid to gamma-carboxyglutamic acids on proteins, which is essential for the calcium binding capacity of Gla proteins (such as osteocalcin). These proteins are found in tissues such as bone, brain, pancreas and lungs, showing that Gla proteins have further important functions. Low intakes of the vitamin may be an important factor for osteoporosis and possibly also for atherosclerosis. The level of vitamin K1 in the Norwegian diet (purchase level) is estimated to be 60 micrograms K1/day before correction of waste. This level is lower than the recommended dietary allowance (1 microgram/kg body weight/day). INTERPRETATION: There is a discussion in the literature of whether the allowances should be considerably higher (375 micrograms K1/day). Deep green vegetables and soybean oil are the best sources of vitamin K1, while cheese gives some K2. On the basis of this knowledge about the importance of vitamin K and osteoporosis, an intervention test should be done with respect to the high incidence of osteoporosis in Norway. Analysis of Norwegian foods for vitamin K1 and K2 is needed.

Tidsskr Nor Laegeforen. 2001 Sep 20;121(22):2614-6

The riddle of vitamin K1 deficit in the newborn.

Vitamin K in the fetus and newborn is maintained at levels less than that necessary to achieve full gamma-carboxylation of the K-dependent proteins, including those required for hemostasis. As the infant matures and even into adulthood, there is no significant storage pool for this vitamin, and a K1-deficient state can be produced by placing an adult on a K-deficient diet for 7 to 10 days. Questions arise as to why the level of vitamin K is so rigidly controlled and why the placental gradient in humans and other mammals maintains the fetus in a K- “deficient” state. The evidence is reviewed that suggests that K-dependent proteins are ligands for receptor tyrosine kinases, which, in the rapidly proliferating cell milieu of the fetus, control growth regulation. Increased stimuli may result in growth dysregulation whereas conversely, the further depletion of vitamin K-dependent proteins, as in warfarin toxicity, depletes the required stimuli for normal embryogenesis. These findings argue for the need for tightly controlled levels of vitamin K consistent with normal embryogenesis.

Semin Perinatol. 1997 Feb;21(1):90-6

Effects of vitamin K2 on osteoporosis.

Vitamin K2 is a cofactor of gamma-carboxylase, which converts the glutamic acid (Glu) residue in osteocalcin molecules to gamma-carboxyglutamic acid (Gla), and is, therefore, essential for gamma-carboxylation of osteocalcin. Available evidence suggests that vitamin K2 also enhances osteocalcin accumulation in the extracellular matrix of osteoblasts in vitro. Osteocalcin-knockout mice develop hyperostosis, suggesting that the Gla-containing osteocalcin promotes normal bone mineralization. Although the precise role of osteocalcin in bone mineralization remains obscure, it probably regulates the growth of hydroxyapatite crystals. Furthermore, vitamin K2 also inhibits the expression of the osteoclast differentiation factor (ODF)/RANK ligand, tartrate-resistant acid phosphatase activity, and mononuclear cell formation, and induces osteoclast apoptosis in vitro. There is some evidence indicating that vitamin K2 prevents bone resorption in ovariectomized rats, retards the increase in bone turnover in orchidectomized rats, ameliorates the increase in bone resorption and decrease in bone formation in sciatic neurectomized rats, and prevents the decrease in bone formation in glucocorticoid-treated rats. These findings suggest that vitamin K2 may not only stimulate bone formation but also suppress bone resorption in vivo. Clinically, vitamin K2 sustains the lumbar bone mineral density (BMD) and prevents osteoporotic fractures in patients with age-related osteoporosis, prevents vertebral fractures in patients with glucocorticoid-induced osteoporosis, increases the metacarpal BMD in the paralytic upper extremities of patients with cerebrovascular disease, and sustains the lumbar BMD in patients with liver-dysfunction-induced osteoporosis. Vitamin K deficiency, as indicated by an increased circulating level of undercarboxylated osteocalcin, may contribute to osteoporotic fractures. Even though the effect of vitamin K2 on the BMD is quite modest, this vitamin may have the potential to regulate bone metabolism and play a role in reducing the risk of osteoporotic fractures. No randomized well-controlled prospective studies conducted on a sufficiently large number of patients have been reported yet, therefore, further studies are needed to confirm the efficacy of vitamin K2 in the treatment of osteoporosis.

Curr Pharm Des. 2004;10(21):2557-76

Role of vitamin K2 in the treatment of postmenopausal osteoporosis.

Vitamin K2, raloxifene, and bisphosphonates, such as etidronate, alendronate, and risedronate, are widely used in the treatment of postmenopausal osteoporosis in Japan. A meta-analysis study has demonstrated the efficacy of anti-resorptive agents: raloxifene and etidronate have been shown to reduce the incidence of vertebral fractures, and alendronate and risedronate have been shown to reduce the incidence of both vertebral and hip fractures. Furthermore, a report of the World Health Organization (WHO) has provided evidence from a randomized controlled trial suggesting that vitamin K2, which may stimulate bone formation via gamma-carboxylation of osteocalcin and/or steroid and xenobiotic receptors (SXRs), reduces the incidence of vertebral fractures, despite having only modest effects on the bone mineral density (BMD). Based on the weight of the currently available evidence, it is recommended that alendronate and risedronate, rather than vitamin K2, should be chosen initially for the treatment of postmenopausal osteoporosis, because these agents have been shown to be the most efficacious for reducing the incidence of both vertebral and hip fractures among the current range of commercially available agents. However, the more potent anti-fracture efficacy of combined treatment with the anti-resorptive and commercially available anabolic agents may need to be established. Some studies have shown that combined treatment with a bisphosphonate and vitamin K2 may be more effective than treatment with a bisphosphonate alone in preventing vertebral fractures. On the other hand, the results of a preclinical study do suggest the possible efficacy of combined treatment with vitamin K2 and raloxifene in the prevention of vertebral and hip fractures in postmenopausal women, although no clinical studies have reported on the effects of combined treatment with vitamin K2 and raloxifene in postmenopausal women with osteoporosis. Vitamin K deficiency, as indicated by high serum levels of undercarboxylated osteocalcin, has been shown to contribute to the occurrence of hip fractures in elderly women. Thus, we propose that the important role of vitamin K2 used in combination with bisphosphonates or raloxifene should not be underestimated in the prevention of fractures in postmenopausal women with osteoporosis with vitamin K deficiency.

Curr Drug Saf. 2006 Jan;1(1):87-97

Beyond deficiency: potential benefits of increased intakes of vitamin K for bone and vascular health.

Vitamin K is well known for its role in the synthesis of a number of blood coagulation factors. During recent years vitamin K-dependent proteins were discovered to be of vital importance for bone and vascular health. Recommendations for dietary vitamin K intake have been made on the basis of the hepatic requirements for the synthesis of blood coagulation factors. Accumulating evidence suggests that the requirements for other functions than blood coagulation may be higher. This paper is the result of a closed workshop (Paris, November 2002) in which a number of European vitamin K experts reviewed the available data and formulated their standpoint with respect to recommended dietary vitamin K intake and the use of vitamin K-containing supplements.

Eur J Nutr. 2004 Dec;43(6):325-35

Role of vitamin K and vitamin K-dependent proteins in vascular calcification.

OBJECTIVES: To provide a rational basis for recommended daily allowances (RDA) of dietary phylloquinone (vitamin K1) and menaquinone (vitamin K2) intake that adequately supply extrahepatic (notably vascular) tissue requirements. BACKGROUND: Vitamin K has a key function in the synthesis of at least two proteins involved in calcium and bone metabolism, namely osteocalcin and matrix Gla-protein (MGP). MGP was shown to be a strong inhibitor of vascular calcification. Present RDA values for vitamin K are based on the hepatic phylloquinone requirement for coagulation factor synthesis. Accumulating data suggest that extrahepatic tissues such as bone and vessel wall require higher dietary intakes and have a preference for menaquinone rather than for phylloquinone. METHODS: Tissue-specific vitamin K consumption under controlled intake was determined in warfarin-treated rats using the vitamin K-quinone/epoxide ratio as a measure for vitamin K consumption. Immunohistochemical analysis of human vascular material was performed using a monoclonal antibody against MGP. The same antibody was used for quantification of MGP levels in serum. RESULTS: At least some extrahepatic tissues including the arterial vessel wall have a high preference for accumulating and using menaquinone rather than phylloquinone. Both intima and media sclerosis are associated with high tissue concentrations of MGP, with the most prominent accumulation at the interface between vascular tissue and calcified material. This was consistent with increased concentrations of circulating MGP in subjects with atherosclerosis and diabetes mellitus. CONCLUSIONS: This is the first report demonstrating the association between MGP and vascular calcification. The hypothesis is put forward that undercarboxylation of MGP is a risk factor for vascular calcification and that the present RDA values are too low to ensure full carboxylation of MGP.

Z Kardiol. 2001;90 Suppl 3:57-63

Genomic approaches to bone and joint diseases. New insights into molecular mechanisms underlying protective effects of vitamin K on bone health.

Vitamin K is a nutrient originally identified as an essential factor for blood coagulation. Accumulated evidence indicates that subclinical non-hemostatic vitamin K deficiency in extrahepatic tissues, particularly in bone, exists widely in the otherwise healthy adult population. Both vitamin K1 and K2 have been shown to exert protective effects against osteoporosis. The new biological functions of vitamin K in bone are considered to be attributable, at least in part, to promotion of gamma-carboxylation of glutamic acid residues in vitamin K-dependent proteins, which is shared by both vitamins K1 and K2. A recent evidence of significant correlation between polymorphism of gamma-glutamyl carboxylase gene and bone mineral density supports the role of gamma-carboxylation-dependent actions of vitamin K. In contrast, vitamin K2-specific,gamma-carboxylation-unrelated functions have recently attracted scientific attention. Recent findings of vitamin K2-specific transactivation of steroid and xenobiotic receptor (SXR/PXR) may lead to new research avenue. The impact of genotype of apoE, a major vitamin K transporter, on ostepporosis as well as Alzheimer disease and atherosclerosis, raises a question whether vitamin K is involved in the pathogenesis of these diseases. Molecular bases of coagulation-unrelated pleiotropic actions of vitamin K and its implications in bone health deserve further investigations.

Clin Calcium. 2008 Feb;18(2):224-32

Effect of low dose vitamin K2 (MK-4) supplementation on bio-indices in postmenopausal Japanese women.

It has been reported that treatment with a pharmacological dose (45 mg/d) of menaquinone-4 (MK-4) prevents bone loss in postmenopausal women. However, it is not known whether supplementation with low dose MK-4 has beneficial effects on bone metabolism in healthy women. The aim of this study is to examine the effects of the supplementation of 1.5 mg/d MK-4 for 4 wk on bone and lipid metabolism in healthy postmenopausal Japanese women. The study was performed as a randomized double blind placebo-controlled trial. The participants aged 53-65 y were randomly assigned to 2 groups and supplemented with 1.5 mg/d of MK-4 or a placebo for 4 wk (n=20 for each group). The most marked effects of MK-4 intake were observed on serum osteocalcin (OC) concentrations. Serum undercarboxylated OC (ucOC) concentration decreased, and the gamma-carboxylated OC (GlaOC) and GlaOC/GlaOC+ucOC ratio that indicates the degree of OC gamma-carboxylation increased significantly at 2 and 4 wk compared with that at baseline in the MK-4 group. The serum ucOC and GlaOC concentrations in the MK-4 group were significantly different from those in the placebo group at 2 wk. These results suggest that supplementation with 1.5 mg/d MK-4 accelerated the degree of OC gamma-carboxylation. The concentrations of serum lipids and other indices were not different between the groups at either intervention period. Thus, the additional intake of MK-4 might be beneficial in the maintenance of bone health in postmenopausal Japanese women.

J Nutr Sci Vitaminol (Tokyo). 2009 Feb;55(1):15-21

Response of serum carboxylated and undercarboxylated osteocalcin to alendronate monotherapy and combined therapy with vitamin K2 in postmenopausal women.

Alendronate decreases the risk of femoral neck fracture by suppressing bone turnover, and also decreases the serum total osteocalcin level. A low serum carboxylated osteocalcin level or high undercarboxylated osteocalcin level could be risk factors for femoral neck fracture. Vitamin K mediates the carboxylation of osteocalcin, but the effect of alendronate therapy with or without vitamin K(2) supplementation remains unknown. Forty-eight postmenopausal women were enrolled in a 1-year prospective randomized trial and assigned to alendronate monotherapy (5 mg/day) (group A, n = 26) or vitamin K(2) (45 mg/day) plus alendronate (5 mg/day) (group AK, n = 22). Bone mineral density was measured by dual-energy X-ray absorptiometry at 0 and 12 months; bone turnover parameters were measured at 0, 3, and 12 months. Four patients discontinued alendronate therapy, and we analyzed the remaining 44 patients (23 in group A and 21 in group AK) who completed 1 year of treatment. Alendronate decreased undercarboxylated osteocalcin; carboxylated osteocalcin was not affected. Addition of vitamin K(2) enhanced the decrease of undercarboxylated osteocalcin levels and led to a greater increase of femoral neck bone mineral density. Alendronate monotherapy does not decrease carboxylation of osteocalcin, and combination of vitamin K(2) and alendronate brings further benefits on both osteocalcin carboxylation and BMD of femoral neck in postmenopausal women with osteoporosis.

J Bone Miner Metab. 2008;26(3):260-4

Vitamin K1 supplementation retards bone loss in postmenopausal women between 50 and 60 years of age.

Although several observational studies have demonstrated an association between vitamin K status and bone mineral density (BMD) in postmenopausal women, no placebo-controlled intervention trials of the effect of vitamin K1 supplementation on bone loss have been reported thus far. In the trial presented here we have investigated the potential complementary effect of vitamin K1 (1 mg/day) and a mineral + vitamin D supplement (8 microg/day) on postmenopausal bone loss. The design of our study was a randomized, double-blind, placebo-controlled intervention study; 181 healthy postmenopausal women between 50 and 60 years old were recruited, 155 of whom completed the study. During the 3-year treatment period, participants received a daily supplement containing either placebo, or calcium, magnesium, zinc, and vitamin D (MD group), or the same formulation with additional vitamin K1 (MDK group). The main outcome was the change in BMD of the femoral neck and lumbar spine after 3 years, as measured by DXA. The group receiving the supplement containing additional vitamin K1 showed reduced bone loss of the femoral neck: after 3 years the difference between the MDK and the placebo group was 1.7% (95% Cl: 0.35-3.44) and that between the MDK and MD group was 1.3% (95% Cl: 0.10-3.41). No significant differences were observed among the three groups with respect to change of BMD at the site of the lumbar spine. If co-administered with minerals and vitamin D, vitamin K1 may substantially contribute to reducing postmenopausal bone loss at the site of the femoral neck.

Calcif Tissue Int. 2003 Jul;73(1):21-6

The effects of topical vitamin K on bruising after laser treatment.

BACKGROUND: Pulsed dye laser treatment and other cosmetic procedures result in significant bruising. Claims have been made regarding the efficacy of topical vitamin K in both preventing and speeding the clearing of bruising; however, well-controlled studies are lacking. OBJECTIVE: The purpose of this study is to evaluate the effects of topical vitamin K versus placebo in the prevention and clearing of laser-induced purpura. METHODS: A total of 22 patients were enrolled in this double-blind randomized placebo-controlled study. The patients were divided into pretreatment and posttreatment groups; the 11 patients in the former group applied vitamin K cream to half of their face and vehicle alone to the other half of their face twice daily for 2 weeks before laser treatment. The latter group followed the same procedure for 2 weeks after laser treatment. On day 0, all subjects underwent laser treatment for facial telangiectases using a 585-nm pulsed dye laser. Bruising was rated by the both the patient and physician by means of a visual analogue scale on days 0, 3, 7, 10, 14, and 17. RESULTS: The side of the face treated with topical vitamin K before laser therapy showed no significant difference in bruising as compared to placebo. However, the side of the face treated with vitamin K cream after laser treatment had significantly lower scores of bruising severity when compared with the side treated with placebo. CONCLUSION: Although pretreatment with vitamin K did not prevent bruising after laser treatment, use of vitamin K cream after laser treatment did reduce the severity of bruising, particularly in the initial days of application.

J Am Acad Dermatol. 2002 Aug;47(2):241-4

Helenalin, an anti-inflammatory sesquiterpene lactone from Arnica, selectively inhibits transcription factor NF-kappaB.

Alcoholic extracts prepared form Arnicae flos, the collective name for flowerheads from Arnica montana and A. chamissonis ssp. foliosa, are used therapeutically as anti-inflammatory remedies. The active ingredients mediating the pharmacological effect are mainly sesquiterpene lactones, such as helenalin, 11alpha,13-dihydrohelenalin, chamissonolid and their ester derivatives. While these compounds affect various cellular processes, current data do not fully explain how sesquiterpene lactones exert their anti-inflammatory effect. We show here that helenalin, and, to a much lesser degree, 11alpha,13-dihydrohelenalin and chamissonolid, inhibit activation of transcription factor NF-kappaB. This difference in efficacy, which correlates with the compounds’ anti-inflammatory potency in vivo, may be explained by differences in structure and conformation. NF-kappaB, which resides in an inactive, cytoplasmic complex in unstimulated cells, is activated by phosphorylation and degradation of its inhibitory subunit, IkappaB. Helenalin inhibits NF-kappaB activation in response to four different stimuli in T-cells, B-cells and epithelial cells and abrogates kappaB-driven gene expression. This inhibition is selective, as the activity of four other transcription factors, Oct-1, TBP, Sp1 and STAT 5 was not affected. We show that inhibition is not due to a direct modification of the active NF-kappaB heterodimer. Rather, helenalin modifies the NF-kappaB/IkappaB complex, preventing the release of IkappaB. These data suggest a molecular mechanism for the anti-inflammatory effect of sesquiterpene lactones, which differs from that of other nonsteroidal anti-inflammatory drugs (NSAIDs), indomethacin and acetyl salicylic acid.

Biol Chem. 1997 Sep;378(9):951-61

Effect of Thymol on the spontaneous contractile activity of the smooth muscles.

Effects of Thymol on the spontaneous contractile activity (SCA) have been found in in vitro experiments with circular smooth-muscle strips (SMAs) from guinea pig stomach and vena portae. Thymol was found to possess an agonistic effect on the alpha(1)-, alpha(2)- and beta-adrenergic receptors. Its spasmolytic effect is registered at doses higher than 10(-6)M. Thymol in a dose of 10(-4)M inhibits 100% the SCA of the SMAs and reduces the excitatory effect of 10(-5)M ACH to 35%. It is assumed that Thymol has an analgesic effect through its action on the alpha(2)-adrenergic receptors of the nerve cells. By influencing the beta-adrenergic receptors in the adipose cells, it is possible to induce increased synthesis of fatty acids and glycerol, which is a prerequisite for increased heat release.

Phytomedicine. 2007 Jan;14(1):65-9

Anti-inflammatory activity of thymol: inhibitory effect on the release of human neutrophil elastase.

Elastase, a serine proteinase released by activated human neutrophils, can degrade a wide variety of biomacromolecules including elastin, and is considered a marker of inflammatory diseases. As the logical strategy to protect tissue is to inhibit excessive elastase activity, experimental and clinical researches have concentrated on trying to find efficient elastase inhibitors. As thymol, one of the major components of thyme oil with a phenolic structure, has been credited with a series of pharmacological properties, that include antimicrobial and antioxidant effects, the aim of this study was to explore whether it can also interfere with the release of elastase by human neutrophils stimulated with the synthetic chemotactic peptide N-formyl-methionyl-leucyl-phenylalanine (fMLP). After the neutrophils were incubated with increasing amounts of thymol (2.5, 5, 10, 20 microg/ml), elastase release was initiated by fMLP and measured using MeO-Suc-Ala-Ala-Pro-Val-MCA. The results showed that thymol inhibited fMLP-induced elastase release in a concentration-dependent manner, with the effects of 10 and 20 microg/ml being statistically significant. The behavior of cytosolic calcium mobilization revealed by fura-2 closely resembled that of elastase, thus suggesting that they may be related. The hydrophobic nature of thymol means that it can approach ion channel proteins through the lipid phase of the membrane, alter the local environment of calcium channels and thus inhibit capacitative calcium entry. In brief, thymol inactivates calcium channels machinery, thus triggering a corresponding reduction in elastase. The antibacterial and antimycotic activity of thymol is already well known, but our findings that it inhibits elastase extend our knowledge of the anti-inflammatory activity of this interesting molecule that is already credited with antioxidant activity. These two latter characteristics make thymol a molecule that can have helpful effects in controlling the inflammatory processes present in many infections.

Pharmacology. 2006;77(3):130-6

Thymol, a constituent of thyme essential oil, is a positive allosteric modulator of human GABA(A) receptors and a homo-oligomeric GABA receptor from Drosophila melanogaster.

The GABA-modulating and GABA-mimetic activities of the monoterpenoid thymol were explored on human GABAA and Drosophila melanogaster homomeric RDLac GABA receptors expressed in Xenopus laevis oocytes, voltage-clamped at -60 mV. The site of action of thymol was also investigated. Thymol, 1-100 microm, resulted in a dose-dependent potentiation of the EC20 GABA response in oocytes injected with either alpha1beta3gamma2s GABAA subunit cDNAs or the RDLac subunit RNA. At 100 microm thymol, current amplitudes in response to GABA were 416+/-72 and 715+/-85% of controls, respectively. On both receptors, thymol, 100 microm, elicited small currents in the absence of GABA. The EC50 for GABA at alpha1beta3gamma2s GABAA receptors was reduced by 50 microm thymol from 15+/-3 to 4+/-1 microm, and the Hill slope changed from 1.35+/-0.14 to 1.04+/-0.16; there was little effect on the maximum GABA response. Thymol (1-100 microm) potentiation of responses to EC20 GABA for alpha1beta1gamma2s, alpha6beta3gamma2s and alpha1beta3gamma2s human GABAA receptors was almost identical, arguing against actions at benzodiazepine or loreclezole sites. Neither flumazenil, 3-hydroxymethyl-beta-carboline (3-HMC), nor 5alpha-pregnane-3alpha, 20alpha-diol (5alpha-pregnanediol) affected thymol potentiation of the GABA response at alpha1beta3gamma2s receptors, providing evidence against actions at the benzodiazepine/beta-carboline or steroid sites. Thymol stimulated the agonist actions of pentobarbital and propofol on alpha1beta3gamma2s receptors, consistent with a mode of action distinct from that of either compound. These data suggest that thymol potentiates GABAA receptors through a previously unidentified binding site.

Br J Pharmacol. 2003 Dec;140(8):1363-72

Avenanthramides, polyphenols from oats, exhibit anti-inflammatory and anti-itch activity.

Oatmeal has been used for centuries as a soothing agent to relieve itch and irritation associated with various xerotic dermatoses; however few studies have sought to identify the active phytochemical(s) in oat that mediate this anti-inflammatory activity. Avenanthramides are phenolic compounds present in oats at approximately 300 parts per million (ppm) and have been reported to exhibit anti-oxidant activity in various cell-types. In the current study we investigated whether these compounds exert anti-inflammatory activity in the skin. We found that avenanthramides at concentrations as low as 1 parts per billion inhibited the degradation of inhibitor of nuclear factor kappa B-alpha (IkappaB-alpha) in keratinocytes which correlated with decreased phosphorylation of p65 subunit of nuclear factor kappa B (NF-kappaB). Furthermore, cells treated with avenanthramides showed a significant inhibition of tumor necrosis factor-alpha (TNF-alpha) induced NF-kappaB luciferase activity and subsequent reduction of interleukin-8 (IL-8) release. Additionally, topical application of 1-3 ppm avenanthramides mitigated inflammation in murine models of contact hypersensitivity and neurogenic inflammation and reduced pruritogen-induced scratching in a murine itch model. Taken together these results demonstrate that avenanthramides are potent anti-inflammatory agents that appear to mediate the anti-irritant effects of oats.

Arch Dermatol Res. 2008 Nov;300(10):569-74

Injury enhances TLR2 function and antimicrobial peptide expression through a vitamin D-dependent mechanism.

An essential element of the innate immune response to injury is the capacity to recognize microbial invasion and stimulate production of antimicrobial peptides. We investigated how this process is controlled in the epidermis. Keratinocytes surrounding a wound increased expression of the genes coding for the microbial pattern recognition receptors CD14 and TLR2, complementing an increase in cathelicidin antimicrobial peptide expression. These genes were induced by 1,25(OH)2 vitamin D3 (1,25D3; its active form), suggesting a role for vitamin D3 in this process. How 1,25D3 could participate in the injury response was explained by findings that the levels of CYP27B1, which converts 25OH vitamin D3 (25D3) to active 1,25D3, were increased in wounds and induced in keratinocytes in response to TGF-beta1. Blocking the vitamin D receptor, inhibiting CYP27B1, or limiting 25D3 availability prevented TGF-beta1 from inducing cathelicidin, CD14, or TLR2 in human keratinocytes, while CYP27B1-deficient mice failed to increase CD14 expression following wounding. The functional consequence of these observations was confirmed by demonstrating that 1,25D3 enabled keratinocytes to recognize microbial components through TLR2 and respond by cathelicidin production. Thus, we demonstrate what we believe to be a previously unexpected role for vitamin D3 in innate immunity, enabling keratinocytes to recognize and respond to microbes and to protect wounds against infection.

J Clin Invest. 2007 Mar;117(3):803-11

Vitamin D and the skin.

Along with other organs like prostate, bones and kidney, skin is capable of vitamin D synthesis. Primarily keratinocytes but also macrophages and fibroblasts synthesize active vitamin D from cholesterol precursors by photochemical activation. The synthesized vitamin D functions by binding to nuclear vitamin D receptors. Vitamin D deficiency usually manifests as rickets in childhood although it is today only relevant in diseases characterized by malabsorption due to today’s recommended vitamin D prophylaxis. Excessive doses of vitamin D are the usual cause of increased levels. The most common therapeutic target of vitamin D is psoriasis. Here, topical preparations are usually employed; their anti-proliferative and cell differentiation-promoting action is mediated via binding to cutaneous vitamin D receptors.

Hautarzt. 2008 Sep;59(9):737-42

Vitamin D as an inducer of cathelicidin antimicrobial peptide expression: Past, present and future.

Vitamin D was discovered as the preventive agent of nutritional rickets, a defect in bone development due to inadequate uptake of dietary calcium. However, a variety of studies over the last several years has revealed that vitamin D controls much more than calcium homeostasis. For example, recent research has underlined the key role of vitamin D signaling in regulation of innate immunity in humans. Vitamin D is converted to 25-hydroxyvitamin D (25D), its major circulating form, and then to hormonal 1,25-dihydroxyvitamin D (1,25D) in target cells. We now know that when cells of the immune system such a macrophages sense a bacterial infection they acquire the capacity to convert circulating 25D into 1,25D. Moreover, 1,25D thus produced is a direct inducer of expression of genes encoding antimicrobial peptides, in particular cathelicidin antimicrobial peptide (CAMP). Antimicrobial peptides such as CAMP are vanguards of innate immune responses to bacterial infection and can act as signaling molecules to regulate immune system function. This review covers what we have learned in the past few years about the expression and function of CAMP under physiological and pathophysiological conditions, and addresses the potential future applications of vitamin D analogues to therapeutic regulation of CAMP expression.

J Steroid Biochem Mol Biol. 2010 Mar 17

Manifestations of food allergy: evaluation and management.

The term “food allergy” refers to adverse immunologic reactions to food. Food allergy is usually mediated by IgE antibody directed to specific food proteins, but other immunologic mechanisms can also play a role. The primary target organs for food allergic reactions are the skin, the gastrointestinal tract and the respiratory system. Both acute reactions (hives and anaphylaxis) and chronic disease (asthma, atopic dermatitis and gastrointestinal disorders) may be caused or exacerbated by food allergy. The foods most commonly causing these reactions in children are milk, egg, peanuts, soy, wheat, tree nuts, fish and shellfish; in adults, they are peanuts, tree nuts, shellfish and fish. The diagnosis of food allergy requires a careful search for possible causes, confirmation of the cause(s) with supporting tests, including specific tests for IgE (i.e., prick skin tests, radioallergosorbent tests) and, in some cases, oral food challenges. Treatment consists of elimination of the causal food(s) along with medical treatment, including the prompt self-administration of epinephrine in the event of a serious reaction.

Am Fam Physician. 1999 Jan 15;59(2):415-24

Dietary aspects of adverse reactions to foods in adults.

Dietary considerations play an important role in the diagnosis, treatment and management of immunologic and nonimmunologic reactions to foods. Food diaries and trial elimination diets may prove helpful in identifying the responsible foods. Elimination diets must be monitored carefully for nutritional adequacy and should be used no longer than absolutely necessary; in some instances appropriate vitamin and mineral supplementation may be necessary. Ideally the identification of foods that provoke symptoms should be confirmed by means of double-blind challenge testing. Avoidance of some problem foods is unlikely to cause nutritional problems, but the practical and nutritional implications of allergies to staple foods such as cow’s milk, eggs and wheat are far greater. Nonimmunologic adverse reactions that may mimic food allergic reactions include gastrointestinal disorders, sensitivity to food additives and psychologically based adverse reactions. There may be some degree of tolerance in metabolic disorders, which makes dietary management easier. Sensitivity to food additives necessitates careful scrutiny of food labels. In psychologic adverse reactions to foods, several foods are often involved, which increases the risk of nutritional problems.

CMAJ. 1988 Oct 15;139(8):711-8

Clinical aspects of gastrointestinal food allergy in childhood.

Gastrointestinal food allergies are a spectrum of disorders that result from adverse immune responses to dietary antigens. The named disorders include immediate gastrointestinal hypersensitivity (anaphylaxis), oral allergy syndrome, allergic eosinophilic esophagitis, gastritis, and gastroenterocolitis; dietary protein enterocolitis, proctitis, and enteropathy; and celiac disease. Additional disorders sometimes attributed to food allergy include colic, gastroesophageal reflux, and constipation. The pediatrician faces several challenges in dealing with these disorders because diagnosis requires differentiating allergic disorders from many other causes of similar symptoms, and therapy requires identification of causal foods, application of therapeutic diets and/or medications, and monitoring for resolution of these disorders. This review catalogs the spectrum of gastrointestinal food allergies that affect children and provides a framework for a rational approach to diagnosis and management.

Pediatrics. 2003 Jun;111(6 Pt 3):1609-16

Food allergen avoidance in the prevention of food allergy in infants and children.

Food allergy afflicts an increasing number of infants and children and is associated with both clinical and familial burdens. To help lessen this burden, the Nutritional Committees from the American Academy of Pediatrics and jointly the European Society for Pediatric Allergology and Clinical Immunology and the European Society for Pediatric Gastroenterology, Hepatology, and Nutrition published recommendations to prevent and treat food allergy. Although there is much in common with these recommendations, differences exist. This review compares, contrasts, and reconciles them, presenting the evidence that has led to their statements.

Pediatrics. 2003 Jun;111(6 Pt 3):1662-71

Treating irritable bowel syndrome with a food elimination diet followed by food challenge and probiotics.

OBJECTIVE: In Irritable Bowel Syndrome, the gut-associated immune system may be up-regulated resulting in immune complex production, low-grade inflammation, loss of Class I bacteria, and translocation of inflammatory mediators and macromolecules outside of the GI lumen. Since food intolerance may be one of the reasons for this upregulation, our goal was to investigate the role of food intolerance in IBS patients. METHODS: In this open label pilot study, we enrolled 20 patients with IBS by Rome II criteria (15 women, ages 24-81) who had failed standard medical therapies in a tertiary care GI clinic. Baseline serum IgE and IgG food and mold panels, and comprehensive stool analysis (CSA) were performed. Breath-hydrogen testing and IBS Quality-of-Life (QOL) questionnaires were obtained. Patients underwent food elimination diets based on the results of food and mold panels followed by controlled food challenge. Probiotics were also introduced. Repeat testing was performed at 6-months. We followed up with this cohort at 1 year after trial completion to assess the reported intervention and for placebo effect. RESULTS: Baseline abnormalities were identified on serum IgG food and mold panels in 100% of the study subjects with significant improvement after food elimination and rotation diet (p < 0.05). Significant improvements were seen in stool frequency (p < 0.05), pain (p < 0.05), and IBS-QOL scores (p < 0.0001). Imbalances of beneficial flora and dysbiotic flora were identified in 100% of subjects by CSA. There was a trend to improvement of beneficial flora after treatment but no change in dysbiotic flora. The 1-year follow up demonstrated significant continued adherence to the food rotation diet (4.00 +/- 1.45), minimal symptomatic problems with IBS (4.00 +/- 1.17), and perception of control over IBS (4.15 +/- 1.23). The continued use of probiotics was considered less helpful (3.40 +/- 1.60). CONCLUSION: These data demonstrate that identifying and appropriately addressing food sensitivity in IBS patients not previously responding to standard therapy results in a sustained clinical response and impacts on overall well being and quality of life in this challenging entity.

J Am Coll Nutr. 2006 Dec;25(6):514-22

Serum IgG subclass antibodies to a variety of food antigens in patients with coeliac disease.

Levels of serum IgA, IgG, and IgG subclass antibodies to a variety of dietary antigens were determined by enzyme linked immunosorbent assays in 14 adults with untreated coeliac disease and in 10 disease controls selected because of raised total IgG activities. The untreated coeliacs showed somewhat higher total IgG activity (p approximately 0.05) and significantly raised IgA and IgG1 + IgG3 activities to gliadin but reduced IgG4 activity (p less than 0.02) compared with the controls. High IgA and IgG1 + IgG3 activities were positively correlated (r = 0.67, p less than 0.01), and so were IgG and IgG4 activities (r = 0.64, p less than 0.02). Conversely, a high IgG2 response to gliadin appeared related to a low IgA response (r = 0.55, p less than 0.05). The IgG2 response was most prominent to oat flour antigens, followed by IgG1; and the main response to soy antigens resided in IgG1, followed by IgG2 in both disease groups. There was no difference in antibody activities to oat and soy between the two groups, and raised activity to bovine serum albumin was seldom encountered. The IgA activity to alpha-lactalbumin and ovalbumin tended to be increased in the coeliacs compared with the controls. The IgG4 subclass dominated the IgG response to beta-lactoglobulin and ovalbumin and was often raised to alpha-lactalbumin, especially in the disease controls. The IgG subclass pattern to casein parallelled that to gliadin with dominance of the IgG1- and IgG3-subclass activities, especially in the coeliacs. The phlogistic potential of a response in these two subclasses might be relevant to the pathogenesis of coeliac disease and could contribute to a raised IgA gliadin response by increasing mucosal permeability. IgA activity seemed to be highest against antigens usually involved in IgE mediated food allergy.

Gut. 1992 May;33(5):632-8

Food hypersensitivity and irritable bowel syndrome.

Irritable bowel syndrome is a common condition but its pathophysiology remains poorly understood. Many irritable bowel syndrome patients give a history of food intolerance, but data from dietary elimination and re-challenge studies are inconclusive. Multiple aetio-pathological mechanisms have been postulated. The gut has an extensive immune system but current understanding of processing of food antigens in health and disease is limited. There is no clinically useful marker available to test for food hypersensitivity in irritable bowel syndrome. Researchers have employed both skin tests and serum immunoglobulins (IgG and IgE) as markers of food hypersensitivity in various disorders including irritable bowel syndrome, but published data are equivocal. In this article, the evidence for the role of food hypersensitivity in irritable bowel syndrome is reviewed and, based on the available data, a possible pathophysiological hypothesis has been formulated.

Aliment Pharmacol Ther. 2001 Apr;15(4):439-49

Food-specific IgG4 antibody-guided exclusion diet improves symptoms and rectal compliance in irritable bowel syndrome.

OBJECTIVE: Dietary modification improves symptoms in irritable bowel syndrome (IBS). Identification of offending foods by dietary elimination/re-challenge is cumbersome. IgG4 antibodies to common food antigens are elevated in IBS. The aim of this article was to evaluate the effect of exclusion diet based on IgG4 titres on IBS symptoms and rectal sensitivity and compliance. MATERIALS AND METHODS: The study comprised 25 patients with IBS (3 M, 22 F, mean age 43 years, Rome II criteria). IgG4 titres to 16 foods (milk, eggs, cheese, wheat, rice, potatoes, chicken, beef, pork, lamb, soya bean, fish, shrimps, yeast, tomatoes and peanuts) were measured. Foods with titres >250 microg/l were excluded for 6 months. Symptom severity was assessed with a previously validated questionnaire at baseline, at 3 months and at 6 months. Rectal compliance and sensitivity were measured in 12 patients at baseline and at 6 months. RESULTS: IgG4 antibodies to milk, eggs, wheat, beef, pork and lamb were commonly elevated. Significant improvement was reported in pain severity (p < 0.001), pain frequency (p = 0.034), bloating severity (p = 0.001), satisfaction with bowel habits (p = 0.004) and effect of IBS on life in general (p = 0.008) at 3 months. Symptom improvement was maintained at 6 months. Rectal compliance was significantly increased (p = 0.011) at 6 months but the thresholds for urge to defecate/discomfort were unchanged. CONCLUSIONS: Food-specific IgG4 antibody-guided exclusion diet improves symptoms in IBS and is associated with an improvement in rectal compliance.

Scand J Gastroenterol. 2005 Jul;40(7):800-7

Diagnostic tests for food allergy.

The diagnosis of food allergy is still based primarily on a detailed medical history and comprehensive physical examination. Clinical or laboratory tests only serve as an add-on tool to confirm the diagnosis. The standard techniques include skin prick testing and in-vitro testing for specific IgE-antibodies, and oral food challenges. Properly done, oral food challenges continue to be the gold standard in the diagnostic workup. Recently, unconventional diagnostic methods are increasingly used. These include food specific IgG, antigen leucocyte antibody and sublingual/intradermal provocation tests, as well as cytotoxic food and applied kinesiology and electrodermal testings. These lack scientific rationale, standardisation and reproducibility. There have been no well-designed studies to support these tests, and in fact, several authors have disproved their utility. These tests, therefore, should not be advocated in the evaluation of patients with suspected food allergy because the results do not correlate with clinical allergy and may lead to misleading advice and treatment.

Singapore Med J. 2010 Jan;51(1):4-9

Comparative study of commercial food antigen extracts for the diagnosis of food hypersensitivity.

Single lots of food allergen extracts from three different commercial sources were compared for their efficacy in evaluating immediate food hypersensitivity. Eighty-seven children with atopic dermatitis and food hypersensitivity underwent prick skin testing to a battery of 18 food extracts from each company. Results of skin tests were compared with results of double-blind, placebo-controlled oral food challenges and open challenges to determine the sensitivity, specificity, and predictive indices of each reagent. Negative predictive indices were generally good for all reagents, whereas positive predictive indices were generally poor and showed considerable variation (0% to 79%) between commercial sources. Under the conditions of the study, skin test reagents from two companies showed slightly better agreement with double-blind, placebo-controlled food challenge results than did reagents from the third company. However, with known lot-to-lot variations in extract potency and intrapatient variation in skin test results, these differences probably are not of clinical significance.

J Allergy Clin Immunol. 1988 Nov;82(5 Pt 1):718-26