Evaluation, Treatment, and Prevention of Vitamin D Deficiency

The Endocrine Society has published a new practice guideline on vitamin D deficiency. This summary covers portions of the guideline that are relevant to adult medicine (the pediatric portion is covered elsewhere; JW Gen Med Jun 23 2011). Key points follow:

• Population-wide screening for vitamin D deficiency is not recommended because evidence to support this practice is lacking. However, screening is recommended in adults who are at high risk for deficiency, including those with osteoporosis, obesity, or history of falls.

• Vitamin D deficiency is defined as serum 25-hydroxyvitamin D (25[OH]D) level <20 ng/mL (50 nmol/L); however, serum assays are notoriously variable.

• Recommended dietary intake for adults is at least 600 IU daily (800 IU for those aged >70); however, some at-risk adults might require ≥1500 IU. Few foods contain substantial vitamin D naturally, and many adults eat little vitamin D–fortified food and do not get enough sun exposure to maintain vitamin D sufficiency. Blacks and other dark-skinned people are at higher risk for deficiency than whites.

• Both vitamin D₂ (ergocalciferol) and D₃ (cholecalciferol) are acceptable as supplements.

• Treatment of vitamin D deficiency is indicated mainly for skeletal reasons; evidence also suggests that treatment lowers the incidence of falls in older adults. In contrast, evidence that treatment prevents cardiovascular disease, lowers mortality, or generally improves quality of life is lacking.