What Is Vitamin D Insufficiency? And Does It Matter?

Calcif Tissue Int. 2012 May 15.
Heaney RP.
Creighton University, 601 N. 30th Street, Suite 4841, Omaha, NE, 68131, USA, rheaney at creighton.edu.

The term nutrient "insufficiency," as commonly used, refers to a nutritional status intermediate between classical, severe deficiency, and full normal. As both "deficiency" and "insufficiency" are causes of dysfunction and disease, there is no biological basis for a distinction between them.

What is important to note is that, in the case of vitamin D, the preponderance of the evidence indicates that there is real, preventable disease in the range of vitamin D status values now labeled "insufficient."
PMID: 22585187

From the conclusion

Additionally, it must be noted in closing that

• (1) there is no consensus with regard to the vitamin D status that represents true adequacy and
• (2) there is a substantial and growing body of evidence indicating that the lower end of
  the adequate range is at least as high as 32 ng/mL (80 nmol/L) and, by some criteria, 40 ng/mL (100 nmol/L).

The fact that this value is higher than that recently recommended by the IOM may be due in large part to their use of a drug-based approach to evaluating efficacy, rather than one based on physiological criteria.

PDF, which was available to the public Dec 2012, is attached at the bottom of this page