“The problem is, there are not any good guidelines on what a normal level should be,” Dr. Greer said. “In the wintertime, everybody in the United States has pretty low levels, but they go up in the summertime, and most of us don't get rickets.”
The AAP recommendation to consume at least 400 IU/day of vitamin D is based largely on studies of non-Hispanic white infants and may not be optimal for other races, he added. “Nobody has looked at large numbers of African American infants” and vitamin D.
Meanwhile, the “inflammatory” reports about vitamin D deficiency appearing in the medical literature “are driving people at the NIH [National Institutes of Health] Office of Dietary Supplements crazy,” Dr. Greer said.
The study investigators and physicians mentioned in this story reported having no potential conflicts of interest related to these topics.