Dr. Kirit Tolia, chief of endocrinology at Providence Hospital in Southfield, Mich., said his sense is that replacing vitamin D in such critically ill patients may be too late. "If you go into illness with a significant vitamin D deficiency, it makes whatever the underlying cause of the hospitalization worse," he said. For example, if someone is being treated for sepsis -- a serious infection -- if their vitamin D levels are low, it makes it harder for them to fight the infection, he explained.
Tolia added that he wasn't surprised by the findings, because he sees a lot of vitamin D deficiency, but that he was "alarmed at the severity of the deficiency and the prevalence of it."
Additionally, he said he believes that healthy adults should get about 1,000 IUs of vitamin D daily, and that those who are elderly or in poor health should get about 1,500 IUs daily. "That gives them a fair chance of maintaining vitamin D in the normal range," he said.
Learn more about vitamin D and its sources from the U.S. government's Office of Dietary Supplements.
SOURCES: Paul Lee, M.B., endocrinologist, research fellow, Garvan Institute of Medical Research, Sydney, Australia; Kirit Tolia, M.D., chief, endocrinology, Providence Hospital, Southfield, Mich.; David Weinstein, M.D., nephrologist, Beaumont Hospital, Royal Oak, Mich.; April 30, 2009, New England Journal of Medicine