AnemiaExposure to sunlight

Solar ultraviolet radiation destroys folate1 2.

One of the effects of reduced folate is increased risk of anemia1.

Thus, skin pigmentation has adapted to where people live for many generations to protect against folate destruction and the adverse effects of free radicals while at the same time being light enough to permit adequate vitamin D production3.

Thus, too much ultraviolet exposure could contribute to risk of anemia unless the dietary folate supply was large enough.

Page last edited: 08 May 2011


  1. Branda, R. F. Eaton, J. W. Skin color and nutrient photolysis: an evolutionary hypothesis. Science. 1978 Aug 18; 201 (4356): 625-6.
  2. Fukuwatari, T. Fujita, M. Shibata, K. Effects of UVA irradiation on the concentration of folate in human blood. Biosci Biotechnol Biochem. 2009 Feb; 73 (2): 322-7.
  3. Jablonski, N. G. Chaplin, G. Colloquium paper: human skin pigmentation as an adaptation to UV radiation. Proc Natl Acad Sci U S A. 2010 May 11; 107 Suppl 28962-8.