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The Vitamin D deficiency controversy.

There is considerable controversy on how to define true vitamin D deficiency. The following is a general consensus (opinion of experts).

Serum total 25(OH)D

<10 ng/mL = Vitamin D deficiency

10-29 ng/mL = Vitamin D insufficiency

>30 ng/mL = optimal Vitamin D

From the laboratorian point of view, it is VERY important to note that these are NOT reference ranges based on a population of samples because many ambulatory, asymptomatic, ostensibly healthy people have vitamin D insufficiency. Much like a fasting cholesterol level, these are clinically recommended ranges.

Most agree with the definition of deficiency. However, the definition of insufficiency is controversial as demonstrated in the next several slides.