Age, vitamin D, and solar ultraviolet.
Holick
M F
MF
Matsuoka
L Y
LY
Wortsman
J
J
D000328:Adult; D000368:Aged; D000375:Aging / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D012867:Skin / Q000378:metabolism / Q000528:radiation effects*; D013472:Sunlight; D014466:Ultraviolet Rays; D014807:Vitamin D / Q000096:biosynthesis*
D014807:Vitamin D