Vitamin D = Confusing

There is a lot of confusion when it comes to Vitamin D, and to be honest, the reason is that even the professionals are confused. Researchers still can't tell you exactly how much Vitamin D you should take or how much time you should spend in the sun a day. All they have is recommendations based on research - but, nothing is set in stone. So, here is what is known as of now.

The current government recommendations for daily Vitamin D consumption is 200 IUs (international units) for those up to 50, 400 IUs up to 70, and 600 IUs for those over 70. However, most professionals would agree, that these are low estimates. Vitamin D's original claim for fame was bone health; however, it has recently been strongly linked to heart health, diabetes, hypertension, multiple sclerosis, and several cancers. The current barriers between people and adequate sources of Vitamin D are lack of sun exposure due to less time spent outdoors and sunscreen use, dark skin complexions, internal conversion issues (ex. kidney issues), and obesity. The amount of Vitamin D that a person needs varies greatly, and is based on age, weight, % body fat, latitude, skin coloration, season, sunblock use, sun exposure and illness. Generally, the old need more than the young, big more than little, northern more than southern, winter more than summer, darker more than fair skinned, and ill more than well.

It was recently said that those living north of Atlanta can not get enough Vitamin D naturally because the sun does not rise far enough for the Ultraviolet B rays (the rays that convert Vitamin D into the active form within the body) cannot penetrate the atmosphere.

Why does it matter? Well, because of Vitamin D deficiency's connection with heart disease, certain types of cancer and diabetes. A study conducted at the University of Minnesota even found a connection between Vitamin D and weight loss results, stating that those who were Vitamin D deficient lost less weight than those who had adequate amounts.

Some experts would tell you that if you don't sunbathe regularly (at least once a week) year round, you need to supplement those less than 1 with 1,000 IUs daily, those over 1 with 1,000 IUs of D3 per 25 pounds of body weight, and well adults with 5,000 IUs. They suggest that you need a 25-hydroxyvitamin D test within 2-3 months after beginning supplementation, and to adjust your intake accordingly. (25 (OH)D can be tested to tell you your Vitamin D level - low levels make it impossible for your body to store Vitamin D - it is the best way to test, and it can be done at most physician's offices)

There is danger with toxic levels of Vitamin D, but you would have to intake extreme amounts - over 40,000 IUs daily. To put these amounts in perspective - 1 cup of milk has about 241 IUs of Vitamin D, 1 tsp of fish oil has about 450, and 3 oz of Salmon has about 650.

So, if you feel you are in danger of low Vitamin D levels, don't ignore it! It is important. Ask your doctor before starting any new supplement. My suggestion would be to try and eat fish as much as you can (2-3Xs/week) or take a fish oil supplement - that way you get your Vitamin D and Omega 3s and 6s! Double Bonus!

Resources:

Vieth, R. (1999). Vitamin D supplementation, 25-hydroxyvitamin D concentration, and safety. American Journal of Clinical Nutrition. 69(5), 842-856.

Kotz, D. (2005). Time in the sun: how much is needed for vitamin D? U.S. News and World Report.

eatright.org

John Jacob Connell, MD - Executive Director of the Vitamin D Council