Table 8 Source and dose of vitamin D, side effects, and potential toxicity:

Reported side effects of vitamin D include nausea, vomiting, headache, metallic taste, vascular or nephrocalcinosis, and pancreatitis. Reported contraindications to vitamin D include hypercalcemia in sarcoidosis; metastatic bone disease148; other granulomatous diseases, such as tuberculosis and Crohn disease (active phase) that have disordered vitamin D metabolism in activated macrophages149; and Williams syndrome150 (infantile hypercalcemia).

Maximum sun exposureNo known vitamin D toxicity, but too much exposure to UVB (burns) results in increased risk of skin cancer10 000 IU (oral equivalent easily achieved with full-body exposure and results in levels of 148–163 nmol/L); in lifeguards exposed to the sun, kidney stones are more common151
About 10 to 15 min of sun exposure of hands and arms midday when sun is overhead needed to achieve daily requirement (about 400 IU)No known side effects; too much exposure to UVB (burns) results in increased risk of skin cancerDark skin requires 4 times as much sun exposure to get the same dose
Use of 2000 IU in African Americans (after 1 y)No known side effectsFailed to achieve a level of 80 nmol/L in 40% of patients53
Use of 4000 IU for 6 moImproved mood the only side effect notedAverage level of 25-hydroxyvitamin D was 110 nmol/L,51 a level seen with adequate sun exposure; no increase in serum calcium noted
4000 IU for 3 moNo notable side effects52
Use of vitamin D2 (synthetic analogue)Several metabolites with unknown side effectsToxicity reported using higher levels152,153
  • UVB—ultraviolet B.

  • * Vitamin D3 unless specified.