As understanding of Vitamin D increases, it is becoming apparent that its most active form, Vitamin D3 (calcitriol), may offer protection against a variety of radiation-induced damages. Vitamin D’s protective action is carried by a wide variety of mechanisms, including cell cycle regulation and proliferation, cellular differentiation and communication, and programmed cell death (apoptosis).

A paper on the subject argued that vitamin D should be considered among the prime nonpharmacological agents that offer protection against low radiation damage and radiation-induced cancer -- or even the primary agent.

According to the paper in the International Journal of Low Radiation:

"... [O]ur understanding of how vitamin D mediates biological responses has entered a new era ... In view of the evidence that has been presented here, it would appear that vitamin D by its preventive/ameliorating actions should be given serious consideration as a protective agent against sublethal radiation injury, and in particular that induced by low radiation".