Effect of Vitamin D and Omega-3 Fatty Acid Supplementation on Anemia Incidence Among Older Adults: the VITAL Trial Open Access

1. Vitamin D supplementation did not significantly reduce the incidence of anemia at 2-years in older adults.

2. Omega-3 fatty acid supplementation did not significantly reduce the incidence of anemia at 2-years in older adults.

Vitamin D and marine-derived long chain n-3 (omega-3) fatty acids (FA) may represent a novel intervention to prevent anemia of inflammation. We report the results of an ancillary study of the larger VITamin D and OmegA-3 TriaL (VITAL), which looked at the effect of vitamin D and/or omega-3 FA supplementation on incidence of anemia in midlife and older adults. VITAL is a randomized, double-blinded, placebo-controlled trial, with a two-by-two factorial design. We focus on a sub-cohort of 839 participants without baseline anemia evaluated at the Boston Clinical and Translational Science Center. The primary end point was incidence of anemia (hemoglobin < 13 g/dL for men and < 12 g/dL for women measured at 2-years). The secondary end point was change in hemoglobin from baseline to 2-years. Incidence of anemia in our cohort was 9.3% over 2 years. Neither vitamin D nor omega-3 FA had significant effect on anemia incidence (OR 0.94, 95% CI 0.59-1.51; OR 1.31, 95% CI 0.82-2.09 respectively) or change in hemoglobin from baseline to 2-years. There were no significant differences when stratified by race, sex, BMI, or baseline vitamin D level. Omega-3 FA had a statistically significant effect on change in hemoglobin in participants with baseline CRP > 3 mg/L (p-interaction = 0.047), while vitamin D had an effect in participants with lower than median baseline total fish intake (p-interaction = 0.001). Supplementation with vitamin D or omega-3 FA, or their combination, did not reduce incidence of anemia in midlife and older adults. The trial was registered at www.clinicaltrials.gov as NCT01169259.