Mary Talley Bowden on vitamin d: what the evidence says · JRE #2335
SUBJECT: VITAMIN D
Not a true/false call. Every claim is logged with its sources; read the exhibits below.
It's so common that I think the number was 74% of people in the country are deficient in vitamin D.
What the evidence says 01 / RECORD
National estimates from NHANES do not support a 74 percent deficiency rate. An analysis of NHANES 2001 to 2018 (71,685 participants) found combined moderate and severe deficiency (serum 25(OH)D below 50 nmol/L) at about 24.6 percent, with insufficiency at 40.9 percent and sufficiency at 34.5 percent. Using the National Academy of Medicine thresholds, NHANES 2011 to 2014 found only 5.0 percent at risk of deficiency and 18.3 percent at risk of inadequacy, meaning roughly 73 percent of the population was sufficient. A higher cutoff of 20 ng/mL (50 nmol/L) yields the largest common figure, about 41.6 percent deficient overall, and the 82.1 percent rate reported at that threshold applies specifically to Black Americans, not the whole country. The 74 percent figure appears to conflate deficiency with the broader insufficient plus deficient categories or is simply overstated: it is Exaggerated.