This post is the first in a new series to answer frequently asked questions by our naturopathic doctor, Diana Quinn, ND. To submit a question for a future post, email firstname.lastname@example.org.
Q: How much vitamin D should I be taking?
A: The best way to determine how much vitamin D you need is to test your level with a simple blood test. The reference range for normal vitamin D levels is 25-50, but research indicates that optimal levels are at the higher end of the range, between 50-100, especially for patients with chronic illness or increased risk. If you are deficient (<25) or insufficient (between 25-35) you may benefit from high-dose supplementation to bring your levels up. The standard dosage for prescribed vitamin D treatment is 50,000 IU once per week, which averages out to about 7500 IU daily. This dosage usually needs to be maintained for about 3 months and then levels re-tested. The best form of vitamin D to take is D3, which can be found in a liquid or pill form. Maintenance doses of vitamin D for adults are 2000-4000 IU, though some people seem to require higher daily maintenance dosing to keep their levels in the optimal range. Remember that vitamin D is a fat-soluble nutrient, which means that it is stored in the fat and can accumulate in the body, so more is not always better for long-term supplementation. Symptoms of excess vitamin D are nausea, increased thirst and urination, and the development of kidney stones. However, more people likely are deficient or require much more vitamin D than they are getting than are at risk for too much. Consult your naturopathic doctor or general physician for advice on what dosage is right for you.