Vitamin Power Proving Strong

BOSTON and AURORA, Colo.—The Archives of Internal Medicine published two studies on vitamins confirming their need for a healthy lifestyle. Data from a large cohort of women with high risk for cardiovascular disease (CVD) indicated daily supplementation with folic acid, vitamin B6 and B12 may reduce the risk of age-related macular degeneration (AMD) (2009;169(4):335-41). The randomized, double blind, placebo-controlled trial included 5,442 (5,205 of which were no diagnosed with AMD) female health care professionals 40 years or older with preexisting CVD or three or more CVD risk factors. Women were randomly assigned to receive a combination of 2.5 mg/d of folic acid, 50 mg/d of pyridoxine hydrochloride (vitamin B6), and 1 mg/do of cyanocobalamin (vitamin B12) or a placebo. After an average of 7.3 years of treatment and follow-up, there were 55 cases of AMD in the combination treatment group and 82 in the placebo group. For visually significant AMD, there were 26 cases in the combination treatment group and 44 in the placebo group.

In the second study, conducted at the University of Colorado Denver School of Medicine, Aurora, researchers concluded vitamin D levels were inversely associated with recent upper respiratory tract infections (URTI) (2009;169(4):384-390). A secondary analysis of the Third National Health and Nutrition Examination Survey, a probability survey of the U.S. population conducted between 1988 and 1994 was performed. Researchers examined the association between serum 25-hydroxyvitamin D (25[OH]D) level and recent URTI in 18,883 participants 12 years and older. The median serum 25(OH)D level was 29 ng/mL and 19 percent of participants reported a recent URTI. Recent URTI was reported by 24 percent of participants with 25(OH)D levels less than 10 ng/mL, by 20 percent with levels of 10 to less than 30 ng/mL, and by 17 percent with levels of 30 ng/mL or more (P<0.001). Even after adjusting for demographic and clinical characteristics, lower 25(OH)D levels were independently associated with recent URTI. The association between 25(OH)D level and URTI seemed to be stronger in individuals with asthma and chronic obstructive pulmonary disease.