New Guidelines Suggest Higher Doses of Vitamin D
Endocrine Society Says Vitamin D Deficiency May Be Common in U.S.
Why Take Vitamin D? continued...
What the evidence does show is that vitamin D helps the body use calcium to prevent bone loss and to build stronger bones, and that vitamin D prevents falls in the elderly by improving muscle function.
A new study, reported at the annual meeting of the Endocrine Society by Weill-Cornell researcher Richard Bockman, MD, PhD, shows that people are seven times more likely to benefit from the bone drugs Actonel, Boniva, Fosamax, and Zometa if their vitamin D levels are at or above 33 ng/mL.
Why is there so little data on vitamin D and non-bone diseases? Only recently have researchers realized that vitamin D is not harmful at the new, higher doses. Few studies used enough vitamin D to raise blood levels of 25(OH)D above 30 ng/mL.
On the positive side, there is very little evidence that increasing vitamin D levels to 30 to 100 ng/mL is any harm to children or to adults -- except in some people with granuloma-forming disorders or lymphoma.
Recommended Vitamin D Doses
Last November, the Institute of Medicine (IOM) released guidelines suggesting that most Americans and Canadians get enough vitamin D, and recommending modest doses of vitamin D supplements. The new treatment guidelines point to new data suggesting that the IOM recommendations "may be inadequate."
The new guidelines recommend different doses of vitamin D for those at risk of vitamin D deficiency:
- Age 0 to 1 year: 400 to 1,000 International Units (IU) daily
- Age 1 to 18 years: 600 to 1,000 IU daily
- All adults over age 18: 1,500 to 2,000 IU daily
- Pregnant or nursing women under age 18: 600 to 1,000 IU daily
- Pregnant or nursing women over age 18: 1,500 to 2,000 IU daily
Because fat stores vitamin D, obese people may need to take two or three times the usual dose of vitamin D.
The guidelines recommend much larger doses of vitamin D, for a very limited time, for people trying to get their vitamin D levels back up to 30 ng/mL. Such doses should be taken under a doctor's supervision.
The new guidelines, announced at the annual meeting of the Endocrine Society in Boston, will appear in the July issue of the Journal of Clinical Endocrinology and Metabolism.