Which of the Following Is a Feature of Vitamin D

Which of the following is a feature of vitamin D?

A) Toxicity from vitamin D may result from overexposure to the sun
B) Requirements are much higher in the elderly due to degenerative bone diseases
C) Fortification of milk with the vitamin is common in order to provide people with a reliable source
D) Absorption from most food sources is very poor,necessitating the enrichment of grain products