It is hard to say if the low folate levels start the problem with the neurotransmitters or if the depression leads to a low intake of folic acid which leads to problems with the neurotransmitters. Folic acid supplementation has helped some patients with depression. Neural tube defects. Me galoblastic anemia is the result of folate or Vitamin B12 deficiency. There is evidence of defective DNA synthesis when there is not sufficient folate or Vitamin B12 in the diet.
Heart disease is increased when there are high homocysteine levels in the blood.
Homocysteine levels increase with the lack of folate in the diet. The high homocysteine levels are thought to hasten plaque formation in the arteries. Subacute combined degeneration of the spinal cord is associated with both vitamin B12 and folate deficiency. This is a degeneration of the spinal cord. This disorder was once thought to be only due to vitamin B12 deficiency, but folate is now also implicated.