The evolution of the human dataset relevant to vitamin D safety has been as rapid as that for efficacy. In the past decade, a large number of well-designed human clinical trials have been published involving relatively high doses of vitamin D in a range of populations and subgroups. These data, combined with a general scientific consensus of serum 25(OH)D levels as the marker for vitamin D status, have drastically informed our knowledge regarding the safety of vitamin D. Presented in this publication is an updated risk assessment of vitamin D based on the most recently published human clinical trials.