Vitamin D Deficiency

What is vitamin D? (Continued)

The guidelines for how much vitamin D we need were updated in 2010 by the Institute of Medicine (IOM). They were set based on the evidence for bone health and assumed that there was limited sun exposure. The recommended dietary allowance (RDA) for vitamin D is as follows:

  • 600 IU/day for ages 1 to 70
  • 800 IU/day for over 70 years of age
  • 600 IU/day for pregnant and lactating women

These recommendations have been met with a lot opposition by some experts, saying that they are too low. The evidence review that the IOM did was based on 1,000 studies. They were limited by the types of studies and availability of studies to support the benefits linking vitamin D to multiple sclerosis, heart disease, cancer, immunity and autoimmune diseases, cardiovascular and respiratory health, pregnancy, obesity, erythropoiesis, diabetes, muscle function, and aging. They looked for randomization, double-blinding, placebo-controlled studies. The studies take a lot of time and money, and enough subjects have not yet been studied in regard to vitamin D and its effects on each one of these medical conditions. The RDA is set to meet the requirements of most healthy individuals, so the argument for greater levels stems from the fact that higher levels are needed for people with health issues. Still, there is a fine line between what we hope will work and what we know will work.

Reviewed on 7/14/2014