A recently-published clinical trial which appeared in the Journal of Nutrition concluded that vitamin C may mitigate the progressive decline of skeletal muscle mass and function associated with aging, which can lead to the condition sarcopenia, frailty, and a reduced quality of life.
 
“People over 50 lose up to 1% of their skeletal muscle mass each year, and this loss is thought to affect more than 50 million people worldwide,” Prof Ailsa Welch, the lead researcher of this study, said. “It’s a big problem, because it can lead to frailty and other poor outcomes such as sarcopenia, physical disability, type 2 diabetes, reduced quality of life, and death.”
 
Welch said that the potent antioxidant properties of vitamin C may prevent long-term oxidative damage of the cells and tissues within skeletal muscle.
 
“Unopposed these free radicals can contribute to the destruction of muscle, thus speeding up age-related decline,” Welch said. “But until now, few studies have investigated the importance of vitamin C intake for older people. We wanted to find out whether people eating more vitamin C had more muscle mass than other people.”
 
The research team analyzed data sourced from more than 13,000 participants between the ages of 42 and 82 years old involved in the EPIC (European Prospective Investigation into Cancer and Nutrition) Norfolk study. Their skeletal muscle mass was cross-examined with vitamin C levels, which were determined through a combined seven-day food diary and measurements of vitamin C concentrations in the blood.  The greatest percentage contributions of different food groups to the daily vitamin C intake of the population were from fruits, vegetables, potatoes, and fruit juices (84.4% for men and 87.1% for women). One of the studies in the meta-analysis even found that muscle atrophy was reversed by the introduction of vitamin C into the diet.
 
Although the positive associations between vitamin C consumption and skeletal muscle retention were greater for women, statistically significant benefits were seen in men, as well. Women with high intakes of vitamin C had 3.9% greater muscle mass than their female counterparts who were shown to have low vitamin C intakes.
 
Vitamin C is believed to work due to its role in the synthesis of carnitine, and collagen, which is a crucial structural component of skeletal muscle cells and tendons, and carnitine is essential for the metabolism of long-chain fatty acids during physical activity.
 
“This is particularly significant as vitamin C is readily available in fruits and vegetables, or supplements, so improving intake of this vitamin is relatively straightforward,” Dr. Richard Haynoe, from Norwich Medical School, said. “We found that nearly 60% of men and 50% of women were not consuming as much vitamin C as they should, according to the European Food Safety Agency recommendations. We’re not talking about people needing mega-doses. Eating a citrus fruit, such as an orange, each day and having a vegetable side to a meal will be sufficient for most people.”