Vitamin D3
Status
Dietary supplement (US). No FDA-approved drug labeling exists for routine cholecalciferol supplementation, which is sold as a dietary supplement and is not reviewed for efficacy. In Drugs@FDA cholecalciferol appears only inside combination products such as Fosamax Plus D and Infuvite (retrieved 25 October 2026). Prescription vitamin D products for conditions such as hypoparathyroidism and refractory rickets are other forms, such as ergocalciferol and calcitriol, with their own labels.
What it is
A fat-soluble vitamin commonly tracked with bloodwork.
What published research measured
Cholecalciferol, converted in liver and kidney to the active hormone. Deficiency is real, common, and worth correcting — the evidence for treating documented deficiency and for preventing rickets and osteomalacia is solid. The evidence for supplementing people who are not deficient is where expectation and data diverge sharply, and the large trials have mostly come back null: VITAL, randomizing over twenty-five thousand adults, found no reduction in invasive cancer or major cardiovascular events, and subsequent large trials found no reduction in fractures in generally healthy adults without deficiency. Very high intakes are not harmless; hypercalcaemia, hypercalciuria and nephrolithiasis are documented at sustained excessive doses, and one randomized trial found higher-dose supplementation produced greater loss of bone density than a moderate dose.
Source
VITAL randomized trial · Randomized trials of vitamin D supplementation and fracture incidence in healthy adults
Sources
No linked primary source is on file for this entry yet.
Educational use only, never medical advice. No doses.