The U.S. government panel in charge of setting recommended daily intake levels for vitamins recently announced an increase in vitamin D recommendations for all populations in North America. Specifically, the Institute of Medicine report advocated a doubling of vitamin D intake for infants (to 400 IU), a tripling of vitamin D intake for those between ages 1 and 50 (to 600 IU), a 50 percent hike in those ages 51 to 70 (to 600 IU), and a 33 percent increase for those older than 71 years old (to 800 IU).
Several major news outlets, however, including the New York Times and the Wall Street Journal, confused the issue by claiming that the report actually questioned the necessity for extra vitamin D. (For more on the debate, visit NPI Center.)
Here, Dr. Brad Jacobs, MD and Chair of Pharmaca's Integrative Health Advisory Board, weighs in on the sunshine vitamin. Dr. Jacobs, is the former founding medical director and Endowed Chair of the Osher Center for Integrative Medicine Clinical Programs at University of California - San Francisco. People who take regular doses of vitamin D have a significantly lower risk of dying early than those who do not use supplements.
Previous studies have suggested that vitamin D deficiency increases the risk of cancer, heart disease or diabetes, but the new findings indicate that the vitamin provides an even bigger bang, researchers wrote in the Archives of Internal Medicine.
The reasons why are not well understood but the researchers suggested the vitamin might block cancer cells from spreading or boost the immune system. The results were based on a meta-analysis that reviewed 18 separate trials involving nearly 60,000 patients. The doses averaged 528 international units, within the range of most commercially available vitamin D supplements. Those who took vitamin D supplements had a 7 percent lower risk of death. The specific causes of death were not yet evaluated.
We do know that Vitamin D is important for both healthy teeth and bones as well as nerve cells such as in the brain and seems to act as an important regulator of the immune system. It is found naturally in only a few foods like oily fish (salmon, tuna, mackerel and sardines) and fish liver oil. It is often added to milk, cereals and orange juice.
But sunlight is the main source for most people; the ultraviolet rays stimulate the skin to produce vitamin D. Many Americans, however, don't have enough vitamin D in their bodies. Many studies have looked at the relationship between cancer and vitamin D, but they have not been able to pinpoint exactly how vitamin D might influence cancer development, how much of an impact it might have or how much vitamin D would be necessary to have any effect.
Two recent studies suggest getting enough vitamin D could help prevent colon, breast and ovarian cancers. The researchers, from the University of California -San Diego, say taking supplements to get more vitamin D might be an easy, inexpensive way to reduce the number of cancer cases in the US. But other experts say it's too soon to recommend taking vitamin D supplements for cancer prevention.
Harvard Medical School researchers reported in the Archives of Internal Medicine
that high intakes of vitamin D and calcium cut the risk of breast cancer by nearly one-third in pre-menopausal women, but not women past menopause.
The U.S. Institute of Medicine's new levels aren't Recommended Dietary Allowances, or RDAs, because the institute doesn't think there's enough evidence to establish an RDA for vitamin D.
Discuss vitamin D intake with your doctor. And be aware that the Institute of Medicine has declared that 4,000 IUs is the upper tolerable, or safe level, for most people. For babies up to 1 year old, the limit is 1,500 IUs.Take action to protect yourself:
1. Talk to your health provider about the latest research on vitamin D and ask for a blood test to see if you are deficient (<15 ng/ml). Ideal levels are >30 ng/ml.
2. Find good sources of vitamin D in your diet, e.g. oily fish and fortified foods (milk, orange juice, cereals).
3. Get 10-15 minutes of sun exposure on your face/arms or back 2 days per week, then apply sunscreen to reduce the risk of skin cancer.
4. Take 1,000-2,000 IU of vitamin D as a dietary supplement on days that you do not get enough intake from the sun and food. Check the label on your multi-vitamin, since most don't have adequate amounts.