Background: the association between vitamin intake and frailty has hardly been studied. The objective was to assess the association of dietary vitamin intake with incident frailty in older adults from Spain.
Methods: data came from a cohort of 1,643 community-dwelling individuals aged ≥65, recruited in 2008-10 and followed up prospectively throughout 2012. At baseline, 10 vitamins were assessed (vitamin A, thiamine, riboflavin, niacin, vitamins B6, B12, C, D, E and folates) using a validated face-to-face diet history. Incident frailty was identified using Fried's definition as having ≥3 of the following five criteria: unintentional weight loss of ≥4.5 kg, exhaustion, weakness, slow walking speed and low physical activity. Nonadherence to the recommended dietary allowances (RDA) was considered when the intake of a vitamin was below the recommendation. Analyses were performed with logistic regression and adjusted for main confounders.
Results: during a 3.5-year follow-up, 89 (5.4%) participants developed frailty. The odds ratios (95% confidence interval) of frailty for those in the lowest versus the highest tertile of vitamin intake were 2.80 (1.38-5.67), P-trend: 0.004, for vitamin B6; 1.65 (0.93-2.95), P-trend: 0.007, for vitamin C; 1.93 (0.99-3.83), P-trend: 0.06, for vitamin E and 2.34 (1.21-4.52), P-trend: 0.01, for folates. Nonadherence to the RDAs of vitamins was related to frailty for thiamine odds ratio (OR): 2.09 (1.03-4.23); niacin OR: 2.80 (1.46-5.38) and vitamin B6; 2.23 (1.30-3.83). When considering tertiles of RDAs for the 10 vitamins those who met <5 RDAs had a higher risk of frailty, OR: 2.84 (1.34-6.03); P-trend: <0.001, compared to those who met >7.
Conclusion: a lower intake of vitamins B6, C, E and folates was associated with a higher risk of frailty. Not meeting RDAs for vitamins was also strongly associated.