Vitamin D deficiency

In medicine, vitamin D deficiency is "s nutritional condition produced by a deficiency of VITAMIN D in the diet, insufficient production of vitamin D in the skin, inadequate absorption of vitamin D from the diet, or abnormal conversion of vitamin D to its bioactive metabolites. It is manifested clinically as rickets in children and osteomalacia in adults."

Recommended serum levels are 20 ng/mL (50 nmol/L) according to the Institute of Medicine (IOM) and 30 ng/mL (75 nmol/L) according to the International Osteoporosis Foundation and National Osteoporosis Foundation.

Institute of Medicine states:
 * Levels over 20 ng/ml are sufficient
 * Levels 12-20 ng/ml are at risk of deficiency.
 * Levels below 12 ng/ml are deficient.

The IOM based their recommendations in part on a prior systematic review by the Agency for Healthcare Research and Quality.

Epidemiology and prevalence
About a quarter of older adults have levels below 20 ng/mL.

Low levels of vitamin D are common in medical inpatients.

Symptoms
Vitamin D was reported to be associated with widespread musculoskeletal pain like fibromyalgia. However, this was an uncontrolled study and more recent studies make the associated between Vitamin D and non-specific pain doubtful and suggest that earlier recommendations to screen patients with musculoskeletal pain for deficiency of vitamin D may not be justified.

Laboratory test
The serum level of 25-hydroxyvitamin D is the best metabolize to assay.

Treatment
Clinical practice guidelines direct treatment.