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Vitamins / Minerals

Vitamin D

Replenishing Vitamin D - generally, 5,000 to 10,000 IU per day of vitamin D3 is recommended to replete a deficiency in adults. Retest in 4 to 6 months (Articles 123).

Vitamin D supplements are available as vitamin D2 (ergocalciferol) or vitamin D3 (cholecalciferol). Vitamin D3 is the more biologically active form and is most commonly used for repletion. It has been shown to raise vitamin D levels more effectively than D2 (4).

Vitamin D increases the absorption of calcium, and K2 (preferably in the form of mk7) makes sure it gets deposited in the bones instead of soft tissues (prevents arterial calcification) (5).

Vitamin D3 (cholecalciferol) is generally considered the best form because it is more biologically active than vitamin D2 and is more effective at raising serum 25-OHD levels, but vegans and vegetarians may prefer vitamin D2 since it is plant-based (7).

Magnesium is a required cofactor for activation of vitamin D in the liver and kidneys (6).