Vitamin D: Controversies and Facts

Two-thirds of the US population had sufficient vitamin D status from 2001 to 2006, according to the CDC. But during that time, one-fourth were at risk of vitamin D inadequacy and 8% were at risk for vitamin D deficiency.

Health care providers often prescribe vitamin D and calcium supplementation to older patients to reduce their risk of fractures. Severe nutritional rickets and osteomalacia are uncommon diseases that can be caused by vitamin D or calcium deficiencies. 

The results of the Vitamin D Assessment Study showed that a 100,000 IU monthly oral vitamin D dose doesn’t improve bone mass unless serum 25-OHD levels are below 30 nmol/L. Vitamin D supplementation is effective when targeted to high-risk groups: patients with compelling risk factors for vitamin D deficiency and documented low serum 25-OHD.

• Patients may avoid sun exposure because of cultural reasons, personal preferences, comorbidities, or because they take photosensitizing medications. These patients are appropriately prescribed vitamin D supplementation without measuring serum vitamin D levels.

• Providers should check a patient’s vitamin D status if they present with nonspecific symptoms such as fatigue, muscle weakness, or muscle pain. Supplementation is only appropriate if serum vitamin D levels are low.

• No evidence exists for measuring serum 25-OHD in patients who are asymptomatic and lack risk factors for vitamin D deficiency.

Many countries fortify their foods with vitamin D to avoid nutritional deficiencies and optimize the population’s vitamin D status. Providers must know that increasing vitamin D intake in the general population with fortified foods or vitamin supplementation will only result in modest improvements. Health care professionals can have the greatest impact on these patients with nutrition education and monitoring for drug interactions with vitamin D. Patients can avoid osteomalacia and nutritional rickets by ensuring adequate dietary vitamin D and calcium intake.

References
Abrahamsen B. Bespoke or one size fits all-vitamin D fortification, targeted
supplementation in risk groups or individual measurement? Maturitas. 2017;103:1-2.
Looker AC, Johnson CL, Lacher DA, et al. Vitamin D status: United States 2001–2006. NCHS data brief, no 59. Hyattsville, MD: National Center for Health Statistics. 2011.