Causes, Consequences and Public Health Implications of Low B-Vitamin Status in Ageing

Abstract

The potential protective roles of folate and the metabolically related B-vitamins (vitamins B12, B6 and riboflavin) in diseases of ageing are of increasing research interest. The most common cause of folate and riboflavin deficiencies in older people is low dietary intake, whereas low B12 status is primarily associated with food-bound malabsorption, while sub-optimal vitamin B6 status is attributed to increased requirements in ageing. Observational evidence links low status of folate and the related B-vitamins (and/or elevated concentrations of homocysteine) with a higher risk of degenerative diseases including cardiovascular disease (CVD), cognitive dysfunction and osteoporosis. Deficient or low status of these B-vitamins alone or in combination with genetic polymorphisms, including the common MTHFR 677 C → T polymorphism, could contribute to greater disease risk in ageing by causing perturbations in one carbon metabolism. Moreover, interventions with the relevant B-vitamins to optimise status may have beneficial effects in preventing degenerative diseases. The precise mechanisms are unknown but many have been proposed involving the role of folate and the related B-vitamins as co-factors for one-carbon transfer reactions, which are fundamental for DNA and RNA biosynthesis and the maintenance of methylation reactions. This review will examine the evidence linking folate and related B-vitamins with health and disease in ageing, associated mechanisms and public health implications.

Prevalence and predictors of subclinical micronutrient deficiency in German older adults: Results from the population-based KORA-Age study

“…Age-associated declines in muscle mass and strength (sarcopenia), which in turn affect balance, gait, and overall independence [3], have been linked to low 25OHD levels as well [4]. Vitamin B 12 and folate are necessary for one-carbon metabolism and DNA synthesis, and have been investigated in relation to degenerative diseases, including CVD, cognitive dysfunction and osteoporosis [5]. Iron deficiency is the most prevalent nutritional deficiency worldwide and its main consequence is anemia [6], which has been associated with an increased risk of developing dementia in old age [7].…”

Exploring the Etiological Links behind Neurodegenerative Diseases: Inflammatory Cytokines and Bioactive Kynurenines

“…The pro-inflammatory cytokine IFN-γ stimulates formamidase in human microglial cells and macrophages, leading to increased KYN synthesis. The activity of KATs is implicated in neurological and cognitive symptoms and the elderly [124,125]. A higher local KYN concentration is necessary for higher activity of KATs due to its low affinity.…”

“…About 20% of the elderly are observed to have lower dietary vitamin B 6 intake, and vitamin B 6 supplementation improves cognitive performance in the elderly. It was proposed that folate, vitamin B 6 , and vitamin B 12 are associated with cognitive performance [124,125].…”

Are Kynurenines Accomplices or Principal Villains in Dementia? Maintenance of Kynurenine Metabolism

“…About 20% of the elderly have been observed to have lower dietary vitamin B 6 intakes and other nutrients, and a daily intake of 20 mg vitamin B 6 improves vitamin B 6 status in healthy older men and vitamin B 6 supplementation improves cognitive performance in elderly men. It has been hypothesized that folate and vitamins B 6 and B 12 are related to cognitive performance [142,143]. Vitamin B 6 emerged as a good predictor of cognitive performance across cognitive domains, but whether B 6 supplementation can improve cognitive performance is still to be demonstrated through ongoing longitudinal clinical trials.…”