Sunscreen-Slathered Americans Lack Vitamin D

Three-quarters of adults and teens in the US aren't getting enough vitamin D, according to a new study. The report suggests increased use of sunscreen has contributed to a steep rise in deficiency of the vitamin, which is mainly absorbed through sunshine. African Americans are particularly at risk because the extra melatonin in black skin slows the creation of the vitamin, Scientific American reports.

"We were anticipating that there would be some decline in overall vitamin D levels, but the magnitude of the decline in a relatively short time period was surprising," said one of the study's authors. (More vitamin D stories.)