As many as 40% of Americans may be deficient in which of the following vitamin?

Question

Quizplus · Accepted Answer

Vitamin D has been the focus of intense research.More than 50 genes are known to be regulated by vitamin D.The normal adult is presumed to obtain sufficient vitamin D from exposure to sunlight and incidental ingestion through small amounts in foods.However, increasing evidence suggests that vitamin D status is low, especially in people with dark skin, in those who spend little time outside, and in those who live in the northern areas of the country.

As Many as 40% of Americans May Be Deficient in Which