by Dan Roberts
If you are protecting your retinas by avoiding direct sunlight, you may also be depriving yourself of a natural source of vitamin D. This is the vitamin which allows your body to absorb enough calcium for strong bones. It is also important to protect us against muscle weakness and possibly a risk of breast, prostrate, and colon cancer.
In a Reader’s Digest article (“Custom-Fit Vitamins,” by Lisa Davis, November 2001), endocrynologist Michael Holick from Boston University recommended that adults expose their hands, arms, and faces to the sun for at least fifteen minutes three times a week. For people with macular degeneration, this would, of course, require wearing 100% UV and blue light protective sunglasses.
If, however, this kind of exposure concerns you, the alternative is to drink a couple of glasses of milk daily or take at least 600 IU of vitamin D, as recommended by the Institute of Medicine (IOM). If you are over 70, however, at least 800 IU is recommended. This may mean taking additional supplementation, since 9-13 servings of fruits and vegetables a day is suggested by the U.S. Department of Health and Human Services to reach recommended amounts of vitamins, minerals and antioxidants.
These IOM recommendations are for disease prevention. But for optimal health, research recommends as much as 2000 IU. This is well under the safe upper limit of 4,000 IU established by the IOM, and it is obtainable in multivitamin supplements.
A paper published in the May 2007 issue of Archives of Ophthalmology confirmed that supplemental vitamin D was inversely associated with early AMD, but only in individuals who did not consume milk daily. (“Vitamin D Report Probably Falls Short” (Ellen Troyer, CEO, Biosyntrx, Inc., December 3, 2010) The researchers assessed 7,752 individuals, 11% of whom had AMD. They also found that levels of serum vitamin D were inversely associated with early AMD but not advanced AMD. (Study title: Association Between Vitamin D and Age-Related Macular Degeneration in the Third National Health and Nutrition Examination Survey, 1988 Through 1994. Authors: Parekh N, et al.)
In April 2011, new research substantiated the benefits of vitamin D (Millen, A. Archives of Ophthalmology, April 2011;vol 129: pp 481-489). The study found that women under 75 who got the most vitamin D had a 59% decreased risk of developing AMD, compared to women with the lowest vitamin D intake.
Researchers also found that the women who had a blood vitamin D level higher than 38 nmol/L had a 48% decreased risk of early AMD. A blood level of 50 nmol/L is considered sufficient, according to the IOM.