Figure 1.
Seasonal variation in serum 25-hydroxyvitamin D (25(OH)D) concentrations among all participants (black dots; n = 3092) and only monthly participants (small gray squares; n = 167).
Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.