Dr. Collins: Many of US Don't Get Enough Vitamin D
Knight Ridder/Tribune Business News
The amount of research into athletes and metabolism is helping all of us who are physically active.
One area that has been closely studied is the importance of adequate vitamin intake. Among the critical dietary elements, vitamin D has moved to the forefront of the debate about adequate levels. The short version is that we need more - lots more - than what's recommended.
The recommended daily intake of vitamin D is 200 units per day.
Recent research suggests that many of us, even with this level of intake, do not get a high enough level of vitamin D in our blood to adequately manage our active lives.
As someone who is frequently outside kayaking, hiking and biking, I had not even considered that I might be low in vitamin D.
My doctor suggested that I get tested. I was shocked to find out I was low. It was even more shocking because I was taking the recommended amount in my vitamins.
After a little research, this is what I learned:
Vitamin D is a prohormone that is produced by the body in conjunction with sunlight. It is converted to the active element, calcitrol.
The hormone calcitrol has been associated with more than 1,000 genes in the body. There is evidence that inadequate levels of vitamin D are associated with quite a few disorders including:
- 17 varieties of cancer
- Heart disease
- High blood pressure
- Muscle weakness and wasting
- Periodontal disease
In most cases, cancer takes time to develop in our bodies, and there is evidence that chronically low levels of vitamin D can hamper our ability to recognize and stop it.
While most of us know that vitamin D comes from exposure to sunlight, we are repeatedly told not to get too much sun because of the risk of skin damage and cancer.
Therefore, we slap on the sunscreen, and off we go down the trail. The result, at least in my case, is that we do not get enough sunlight to create an adequate level of vitamin D. The farther north we live, the less exposure from sunlight we get. This puts Idahoans at a higher risk for deficiency.
Given the choice, it is better to take a supplement than develop skin cancer or get a sunburn.
You get about 2,000 units of vitamin D each day from an average diet. Most of us who are outdoors on a regular basis get another 1,000 units per day from sun exposure - even with sunscreen.
The problem is, we need an average of 4,000 units per day. Taking the recommended supplement of 200 units can leave you almost 1,000 units short. This leads to the recommendation that we take at least 1,000 units of vitamin D per day as a supplement.
People who are older do not have the ability to synthesize vitamin D as well, so they need more than 1,000 units per day.
If you are interested in your status, you should get your 25 (OH) vitamin D level tested. Your doctor can do a simple blood test as part of your physical. If you are low, your doctor can recommend a dose that will get you back on track.
Some doctors recommend that you take 5,000 units of vitamin D per day for three months and then have your vitamin D level tested. Then, you adjust your vitamin D dose so that you get blood levels that are between 50 and 80 nanograms per milliliter. This is especially important if you are older than 70 or have conditions that might decrease your absorption of vitamins like diabetes or bowel disease.
The bottom line is, you shouldn't rely on your time outdoors to meet your vitamin D needs. Get your level checked and start taking a supplement.
(Paul Collins, M.D. is an orthopedic surgeon specializing in sports medicine at Orthopedic Health Care in Boise, Idaho. Collins is an avid participant in many outdoor activities. Please send your sports medicine questions to firstname.lastname@example.org or at The Idaho Statesman, P.O. Box 40, Boise, ID 83707.)