B Complex Vitamins & Depression

B complex generally refers to supplements containing the chemically distinct B vitamins. These are vitamins B1, B2, B3, B5, B6, B7, B9 and B12. They are water-soluble vitamins that are needed in a number of cellular functions throughout the body. The important contribution of B vitamins to the central nervous system can be appreciated by the dysfunctions that can occur when you have a vitamin B deficiency.

Depression

The National Institutes of Mental Health, or NIMH, says that depression is a common and serious illness. There are several different forms of depression and each has its own characteristic symptoms. There is no known single cause of depression, but it appears to result from a combination of genetic, environmental, biochemical and psychological factors. An MRI of the brain shows that depression makes the brain appear differently and that its communication chemicals may be imbalanced. Family history may play a role, says NIMH.

B Vitamins

It is unknown whether a B-vitamin deficiency is the cause or the result of depression. Given that the chemical reasons for depression are largely unknown, it is difficult for scientists to pinpoint any association, says NIMH. However, it is known that a B-vitamin deficiency correlates with depression. According to the website depression-guide.com, patients with high levels of vitamin B12 respond better to antidepressant treatment of depression than those without. B vitamins seem to play an important role in relieving depression by alleviating the anxiety and restlessness that often accompanies this illness. The website supplementnews.org reports that studies indicate vitamin B6 may alleviate depression associated with eating disorders and premenstrual syndrome. Dietary vitamin B12 can help fight anemia, which can cause depressed moods.

Effects

Vitamin B6 is needed in the brain to manufacture proteins and enzymes, says the National Institutes of Health, or NIH. There is evidence that it plays a role in depression, as well as headaches, seizures and Parkinson's disease. It is needed for synthesizing the neurotransmitters, serotonin, norepinephrine and dopamine. These are chemicals that neurons need to communicate. This is significant since vitamin B6 supplements in children may improve ADHD as well as cognitive behavior. Studies also show vitamin B12 may be associated with dementia, Alzheimer's disease and generalized cognitive decline, says NIH. Also, there appears to be a link between vitamin B12 deficiency and memory loss, mania and psychosis.

Sources

The NIH and U.S. Department of Agriculture, or USDA, recommend that a variety of foods be eaten in order to maintain a proper vitamin supply and to keep the nervous system healthy. Supplements are a good way to get daily vitamins, but natural sources of B vitamins abound in common foods. Examples are breakfast cereals, poultry, fish, eggs and meats. Green leafy vegetables, bananas, peas, beans and breads are other good sources.

Recommended Allowance

The USDA lists the recommended daily allowance for B vitamins: 600 mcg of B9 for pregnant women; 2.4 mcg of B12 for adults; 1.3 mg of B6 for adults ages 19 to 50 and 1.5 mg to 1.7 mg for those older than 50; 1.1 mg to 1.2 mg of B1 for adults; 1.1 mg to 1.3 mg of B2 for adults; and 5 mg to 10 mg of B5 for adults.