Vitamin D: A Rapid Review

Mark A. Moyad, MD, MPH


Dermatology Nursing. 2009;21(1) 

In This Article

Side Effects and Toxicity

Some studies have given healthy individuals 100,000 IU tablets or more once every 4 to 6 months without acute toxicity (Wolpowitz & Gilchrest, 2006). A 21-year-old man or women exposed to summer UVB light generates 10,000 IU (the equivalent of 250 mcg, 25 multivitamin pills of vitamin D, or 100 glasses of milk) of vitamin D in 15 to 20 minutes. However, longer exposure does not produce more vitamin D. Humans were basically built to produce and carry higher levels of vitamin D when exposed to the sun. Previous research suggests that the first sign of real side effects or toxicity of vitamin D occurs at a blood level of greater than 88 ng/ml (220 nmol/L) where abnormally high blood levels of calcium result from too much absorption of calcium from food and that can lead to problems (Bischoff-Ferrari et al., 2006; Wolpowitz & Gilchrest, 2006). Regardless, as mentioned earlier, apart from the acute toxicity of hypercalcemia or hypercalciuria, the long-term implications of blood levels of 70 to 90 ng/ml are not known, and in this author’s opinion, should not be entertained without more long-term safety data.


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