The notion that dietary factors affect cognitive function and subsequently the risk of dementia has increased over the years from a global viewpoint. Because low folate intake has been described to impair cognitive function, we tested the hypothesis that low serum folate concentration is associated with cognitive impairment and an attenuated increase in DNA damage. We investigated the relationship between serum folate concentration, cognitive impairment, and DNA damage among elderly people attending health clinics in Klang Valley, an urban area in Malaysia. Two hundred thirty-two participants, composed of 115 men (49.6%) and 117 women (50.4%), were involved; none of the patients were diagnosed with neuropsychiatric problems, nor where they terminally ill. Sociodemography and health variables were assessed through face-to-face interview. Cognitive impairment review was conducted through an Elderly Cognitive Assessment Questionnaire. The estimation of dietary intake, serum folate concentration, and DNA damage was individually analyzed using validated Dietary History Questionnaires, immunoassay methods, and an Alkaline Comet Assay study (10 mL of peripheral venous blood), respectively. Results indicated that more men had cognitive impairment (33.0%) and DNA damage (27.0% for percentage DNA in tail, 22.6% tail moment) compared with women (25.6%, 15.4%, and 15.4%, respectively) (P < .05 for all parameters), recording an average folate deficiency value of 13.9% (0.2% higher than women). Multivariate binary logistic regression analysis outlined the association of cognitive impairment with older age (odds ratio [OR], 2.74; 95% confidence interval [CI], 1.35-5.57), smoking habits (OR, 5.12; 95% CI, 2.48-10.57), poor serum folate concentration (OR, 3.46; 95% CI, 1.26-9.52), and DNA damage (percentage DNA in tail) (OR, 13.70; 95% CI, 1.36-138.29). In conclusion, this study highlighted the important role of serum folate concentration for cognitive function and provided a concise picture regarding the elevated levels of oxidative DNA damage in peripheral lymphocytes.
Vitamin deficiencies are known to be common among infants residing in low- and middle-income countries but relatively few studies have assessed several biochemical parameters simultaneously. The objective of the study was to describe the status of vitamins (A, D, E, B₆, B12 and folate) in breastfed infants. We measured the plasma concentrations of trans retinol, 25 hydroxy vitamin D, α-tocopherol, pyridoxal 5'-phosphate, cobalamin, folate, methylmalonic acid, homocysteine, hemoglobin and C-reactive protein from 467 randomly selected infants. One in five (22%) was deficient in at least one vitamin. Mean (SD) plasma folate concentration was 73 (35) nmol/L, and no infant in the sample was folate deficient. Vitamin B₆ deficiency and vitamin B12 deficiency was found in 22% and 17% of the infants, respectively. Elevated plasma methylmalonic acid or total homocysteine concentration was found in 82% and 62% of infants, respectively. Fifteen percent of infants were vitamin A deficient and 65% were marginally deficient in vitamin A. Fewer than 5% of infants had low plasma vitamin D concentration or vitamin E concentration (α-tocopherol <9.3 µmol/L). Our results illustrate the importance of continued supplementation campaigns and support the expansion of food fortification and dietary diversification programs that target children and women in Nepal.