Elevated homocysteine can be bad news: it is associated with increased cardiovascular disease risk, adverse neurological outcomes, and poor bone health. Can supplementation with omega-3 fatty acids, both with and without B-vitamins, affect concentrations of homocysteine?
Entries filed under 'Cognitive health'
Vitamin B12 is required for the proper functioning of the brain. There are various ways in which an adequate vitamin B12 status supports neurological function. Vitamin B12 is required for the synthesis of DNA building blocks, and the integrity of DNA, and has epigenetic effects on DNA methylation in the brain. Clinical vitamin B12 deficiency causes neurological symptoms: fatigue, numbness and tingling in the hands and feet, confusion and poor memory. But, can low-normal levels that are above normal deficiency cut-offs also be associated with problems with learning and memory?
Vitamins have many functions and sources. A common function is to be part of an enzyme involved in a metabolic reaction. The brain is particularly metabolically active. In 2002, the Institute of Medicine estimated that 130 grams of carbohydrate were needed daily to provide sufficient glucose for the brain to function. Thinking requires energy. So it is not surprising to read that increasing one’s intake of vitamins and minerals might impact metabolism and the brain.
In a randomized, double blind, placebo-controlled, parallel-groups study of 97 healthy females, Kennedy and colleagues studied the effect of increasing doses of multivitamins/minerals
Vitamin B12 is synthesized by bacteria in our gut or obtained by eating meat, dairy, eggs and fish. When people do not eat animal products, vitamin B12 intake can be low. In the blood, vitamin B12 is primarily bound to transcobalamin and transported to cells. Within cells, vitamin B12 (cobalamin) and its other forms, methylcobalamin and adenosylcobalamin, serve as cofactors to methionine synthase, an enzyme involved in the methylation of DNA and histone proteins. Vitamin B12 metabolites regulate gene expression and are particularly important for brain development.
Out of ~600 carotenoids found in nature, ~50 are found in the diet, 14 are detected in human blood, and only 2 – lutein and zeaxanthin – are selectively deposited in the retina and lens of the eye. Zeaxanthin is concentrated in the macula of the retina whereas lutein is in the periphery. These carotenoids serve as antioxidants, protecting photoreceptor cells against damaging blue light.
Lutein and zeaxanthin are not made in the body so they have to be obtained from the diet. Major sources for both are eggs and corn.