Table 3.

Comparison of Institute of Medicine⁽³⁵⁾ v. Endocrine Society⁽⁵²⁾ cut-points for serum total 25-hydroxyvitamin D (nmol/l)

Interpretation	IOM	Endocrine Society
	Serum total 25(OH)D (ng/ml)*
Deficient	<12	<20
Insufficient	12–20	21–29
Sufficient	20–30	30–100
No added benefit	30–50
Possible harm	>50	>100

^*nmol/l = ng/ml × 2·5.