Table 1.

Classification of Vitamin-D levels (serum 25(OH)D levels) and recommended oral Vit-D dose [9].

Classification	Nanograms (ng/ml)	Nanomoles (nmol/l)	Recommended oral VitD dose
Normal or optimal	≥30	≥75–120	400–4000 IU/day
Insufficient	21–29	51–74	4000–6000 IU/day
Deficient	11–20	26–50	7000 IU/day
Severely deficient (often not distinguished from deficient)	<10	25 or less	10,000 IU/day for 1 month