Brain Chemistry & Nutrition

The brain and spinal cord comprise the majority of the central nervous system (CNS). Their requirements are much the same as other tissues in the body, yet the CNS needs certain nutrients in order to function optimally. When one or more critical nutrients are lacking from the diet, the result can be neurological disturbances of varying degrees.

Brain Function

Before birth, the brain requires folic acid to develop normally, says the National Institutes of Health (NIH). When a mother is deficient in folic acid, the fetus may have part of the brain exposed to its outside surface. This birth defect is called anencephaly. Adult brain cells use vitamin B6 for producing enzymes and for protein metabolism. It is required for making serotonin and dopamine. While still being studied, NIH says it may play a role in developing Parkinson disease, depression and seizures. Vitamin B12 is reported to have various roles in neurons, including DNA synthesis. The University of Maryland Medical Center (UMMC) reports another nutrient, omega-3 fatty acids, can cause vision and other nerve problems in the fetus when lacking in the maternal diet. Its contribution to attention deficit-hyperactivity disorder, depression or schizophrenia is being investigated.

Brainstem and Spinal Cord Function

The fetal brainstem and spinal cord also need folic acid to develop normally, says NIH. Insufficient levels in the mother can cause the birth defect spina bifida, which is when part of the spinal cord is exposed to the outside surface of the fetus's body. Other problems may arise from vitamin B12 insufficiency, according to NIH. These likely result from neuron degeneration, and can appear as difficulty with walking and coordination, as well as spasticity of the limbs.

Peripheral Nerve Function

Neurons of the peripheral nervous system can be affected by low levels of vitamin B6. The effect may be noticeable as neuropathy, or problems with nerve conduction resulting in sensory and motor dysfunction. The NIH also reports either extremely elevated or depressed levels of vitamin B6 can cause neuropathy, although the precise mechanism of this occurrence is unknown. Neuropathy can also take place with vitamin B12 insufficiency. The NIH warns this can manifest as either numbness or weakness in the legs and arms. More severe vitamin B12 deficiency may be observed as bowel and bladder dysfunction and can lead to impotence in males.

Recommended Dietary Allowance (RDA)

The Recommended Dietary Allowance (RDA) established by the NIH for folic acid in pregnant women or women about to become pregnant is 600 mcg daily. The daily RDA for vitamin B6 is 1.3 mg for anyone ages 19 to 50, and 1.7 mg for men and 1.5 mg for women over 50. The daily adult RDA for vitamin B12 is 2.4 mcg. The UMMC warns that daily omega 3-fatty acids from dietary supplements should not exceed 3 grams.

Food Sources

Folic acid is contained in highest concentrations in fortified breakfast cereal, beef liver, asparagus, cowpeas, spinach, green peas, broccoli and white rice. Vitamin B6 is mostly concentrated in foods such as fortified breakfast cereal, various fish, poultry, meats, beans, vegetables and fruit. Vitamin B12 is most highly concentrated in meat, fish, poultry, eggs and milk. Omega-3 fatty acids are mostly concentrated in foods such as tuna, salmon, halibut, nuts and plants.