Aging is associated with chronic low-grade inflammation, sarcopenia, and functional decline. The loss of muscle mass between 40 years and 80 years of age is approximately between 30% and 60% and is associated with disability, illness, and death.

Vitamin C has several functions that may prevent age-related skeletal muscle loss. Vitamin C is involved in the synthesis of carnitine and collagen, and it can reduce oxidative damage to muscle and reduce inflammatory cytokines in the circulation. Although the mechanisms of vitamin C and muscle physiology is known, human clinical studies are lacking.

According to a recent study published in The Journal of Nutrition, researchers investigated cross-sectional associations of dietary and plasma levels of vitamin C and its relationship on muscle mass.

The research team analyzed data from more than 13,000 individuals between the ages of 42 years and 82 years of age. Skeletal muscle mass was estimated using bioelectrical impedance analysis and expressed as a percentage of fat-free mass or standardized by body mass index. Dietary vitamin C intakes were assessed using a 7-day food diary and plasma vitamin C levels were measured. This method has been found to be more accurate than food frequency questionnaires. Each participant recorded all drinks and foods including portion sizes. The Data into Nutrients for Epidemiologic Research (DINER) software was used to document dietary information and convert it into nutrient quantities.

This is the first study to investigate the relationship of dietary and vitamin C levels and the loss of skeletal muscle mass as a sarcopenic risk factor in individuals of middle and older age. As a result, there were significant positive associations between dietary vitamin C intake and measures of fat-free mass using multivariable regression models. Although the associations were significant in both men and women, the results were greater in women. Dietary vitamin C intake was reinforced and validated with plasma vitamin C levels.

These findings demonstrate the importance of obtaining adequate dietary or supplemental vitamin C intake for reducing age-related muscle loss. Interestingly, an animal study demonstrated a reversal of muscle atrophy with the reintroduction of vitamin C into the diet. Other nutrients to consider include vitamin D, magnesium, collagen, branched-chain amino acids (BCAAs), tocotrienols, and probiotics.

By Michael Jurgelewicz, DC, DACBN, DCBCN, CNS

Source: Lewis LN, Hayhoe RPG, Mulligan AA, Luben RN, Khaw K-T, Welch AA. Lower dietary and circulating vitamin c in middle- and older-aged men and women are associated with lower estimated skeletal muscle mass. J Nutr. 2020;nxaa221. doi: 10.1093/jn/nxaa221.