Nutr Res Pract. 2009 Spring;3(1):43-8. Epub 2009 Mar 31.

Chang N, Kim E, Kim KN, Kim H, Kim SY, Jeong BS.

We investigated the nutritional state of B vitamins and the neuropsychological functions in 25 subjects, aged 63.1 +/- 6.3 years, residing in rural areas of Korea. Nutritional states of thiamin, riboflavin, and pyridoxine were assessed enzymatically in the erythrocytes, and folate concentrations were measured microbiologically in the plasma and erythrocytes. A battery of composite neuropsychological test was administered to the subjects. Plasma folate was correlated with the total intelligence score (p=0.049). Folate levels in the erythrocytes were correlated with the performance intelligence scores such as block design (p=0.017) and picture arrangement (p=0.016). The red cell folate was correlated with memory scores such as general memory (p=0.009) and delayed recall (p=0.000). Although it did not reach statistical significance, verbal memory (p=0.053) was highly correlated with the red cell folate. The red cell folate was also correlated positively with the percent of conceptual level response number score (p=0.029), and negatively with the grooved pegboard test score for the non-dominant hand (p=0.010). Fine motor coordination was also influenced by folate nutrition, as finger tapping scores in both hands were significantly correlated with red cell folate (dominant hand; p=0.026, non-dominant hand; p=0.004). Other B vitamins such as thiamin, riboflavin, and vitamin B(6) were not as strongly correlated with neuropsychological function test scores as folate was. These results suggest that folate nutrition influences neuropsychological function test scores significantly in humans. Further studies are needed to explore the relationship between folate or other vitamin B nutrition and neuropsychological functions and the implications thereof.

Michael's Comment: Folic acid supplementation has come under attack recently, with folic acid itself being said to increase risks of cancers. I still take 1,000 mcg of folic acid, which I get in the multivitamin I take, the SuperNutrition Easy-Swallow Opti-Energy Pack. Some new data contradicts an accumulation of older data and says that 1,000 mcg may increase prostate cancer growth. Experts in nutritional biochemistry dispute this. See: http://www.michaelmooney.net/FolicAcidCancer.html and http://www.michaelmooney.net/FolicAcidDoesNotCauseCancer.pdf.