July 27, 2016

Vitamin D Deficiency

How is a vitamin D deficiency diagnosed?

All it takes is a simple blood test to find out if you are deficient in vitamin D, but you need to have the right test done. There are two blood tests for vitamin D. One is 1,25(OH)2D. This is one is not a good measure for your current vitamin D level. It has a short half-life and can be impacted by your parathyroid hormone (PTH), calcium, and phosphorus levels, so it's not a true measure of your vitamin D status. The preferred test is the 25-hydroxyvitamin D, written as 25(OH)D. This is the most accurate measure of your current status as it reflects what you get from your diet, from supplements, and from the sun. It is also the one that the majority of the research studies measures.Again, there are two sets of guidelines written by both the Institute of Medicine (IOM) and the task force for the Endocrine Society. These levels are for serum (blood) 25(OH)D:

  IOM Guidelines Endocrine Society Guidelines
Deficiency Below 12 ng/mL Below 20 ng/mL
Insufficiency 12 to 20 ng/mL 21-29 ng/mL
Adequate Over 20 ng/mL 30-60 ng/mL
Excessive Over 60 ng/mL  

In Europe, vitamin D experts have recommended a minimum of 20 ng/mL and state that more research needs to be done before raising it to 30 ng/mL. The question remains if the ideal level will be altered for people with different medical conditions. One study found that 25(OH)D levels and subsequent (50 years') risk of depression was lower in participants with levels between 20-34 ng/mL. Continue Reading

Reviewed on 6/9/2016