Influences of Vitamin D and Iron Status on Skeletal Muscle Health: A Narrative Review.

There is conflicting evidence of the roles vitamin D and iron have in isolation and combined in relation to muscle health. The purpose of this narrative review was to examine the current literature on the roles that vitamin D and iron have on skeletal muscle mass, strength, and function and how these nutrients are associated with skeletal muscle health in specific populations. Secondary purposes include exploring if low vitamin D and iron status are interrelated with skeletal muscle health and chronic inflammation and reviewing the influence of animal-source foods rich in these nutrients on health and performance. PubMed, Scopus, SPORT Discus, EMBAE, MEDLINE, and Google Scholar databases were searched to determine eligible studies. There was a positive effect of vitamin D on muscle mass, particularly in older adults. There was a positive effect of iron on aerobic and anaerobic performance. Studies reported mixed results for both vitamin D and iron on muscle strength and function. While vitamin D and iron deficiency commonly occur in combination, few studies examined effects on skeletal muscle health and inflammation. Isolated nutrients such as iron and vitamin D may have positive outcomes; however, nutrients within food sources may be most effective in improving skeletal muscle health.

Place of residence modifies the association between acculturation and dietary tools knowledge among Latina WIC participants: a multi-state study.

This cross-sectional study assessed: (a) awareness and knowledge of federal dietary tools (MyPyramid, Food Guide Pyramid (FGP), and food labels (FL)), and (b) the influence of acculturation and state of residence on FGP knowledge (FGPK) indicators among low-income Latina WIC participants (N = 479) living in Connecticut, Ohio, Texas, and California. Participants were familiar with FGP but only 37% recognized MyPyramid. FGPK was highest for fruits (71%) and lowest for the 'breads and cereals' group (12%). Less than half (47%) used FL's when grocery shopping. Living in OH, was associated with the lowest FGPK. Multivariate analyses showed that more acculturated individuals living in CT/CA had better FGPK than participants living in TX and their less acculturated counterparts in CT/CA. The forthcoming revised federal dietary tools need to be adequately disseminated among Latinos, with special emphasis on those with lower acculturation levels, living in rapid emerging Latino communities or in the US-Mexico border.