B vitamins ability to improve the nervous system and human intelligence functions defines an important role for basic nutrition that goes far beyond the old notions of nutritional deficiency diseases. Optimizing folic acid and vitamin B12 intake can be of profound benefit to cognitive ability as well as help maintain optimal function of nerves at every age.

It was previously thought that folic acid and B12 deficiency centered mostly on anemia. If blood levels of these nutrients looked normal and there was no anemia, then it was considered that a person must be getting enough either in the diet or with supplements.

This view of deficiency has changed over the past decade. It is now recognized that these nutrients are crucial for the proper function of various metabolic pathways, especially those involved with the healthy function of nerves. Folic acid is needed to metabolize homocysteine. B12 is needed to metabolize methylmalonic acid. If either homocysteine or methylmalonic acid build up in the blood it reflects nervous system impairment that is handicapping optimal function, and may eventually help cause diseases such as Alzheimer’s. Blood levels of folic acid and B12 can appear normal, with no signs of anemia, yet homocysteine or methylmalonic acid can be elevating. By taking enough folic acid and B12, levels of homocysteine and methylmalonic acid can be normalized, which means that healthy function has been improved. This is a significant nutritional issue of great importance to preserving your mind.

A recent study with infants aged 12-18 months found that as folic acid and B12 levels went up, so did scores on the mental development index. On the other hand, if scores for homocysteine or methylmalonic acid went up, then scores for mental development went down. A nursing mother can take higher levels of B12 or folic acid to support optimal mental skill development in her child, and infants can certainly take a high quality multivitamin containing B12 and folic acid.

The benefits of B12 and folic acid apply throughout adulthood. Regular intake of B12 and folic acid has been shown to improve memory in stressed adults. Low B12 is directly linked to poor cognitive performance and brain shrinkage in adults.

Folic acid and B12 are especially important during aging, as elevations in either homocysteine or methylmalonic acid impair brain function in the elderly. In the beginning phases of elevation these compounds are a form of toxic brain stress. Ongoing problems can contribute to significant cognitive decline, even Alzheimer’s. Indeed, a lack of folic acid is typically found in the cerebral spinal fluid of patients with Alzheimer’s, consistent with elevated blood levels of homocysteine. Other researchers demonstrated that methylmalonic acid levels are high in Alzheimer’s patients and that as B12 levels rise the risk for Alzheimer’s goes down. B12 has also been shown to protect against frailty in the elderly. The most recent research continues to show a lack of both folic acid and B12 in age-associated cognitive decline.


Collectively, these studies show that folic acid and B12 are needed for your brain to function properly. They are commonly lacking at levels that optimize your brain’s function – a direct support for your mental ability and potential.

A recent analysis of all B12 studies shows that as the intake of B12 doubles, blood levels of B12 rise by 11 percent and the levels of methylmalonic acid decline by 7 percent. To normalize methylmalonic acid levels some individuals may need 1 mg (1,000 mcg) – 2 mg (2,000 mcg) per day of B12. This dose is many times higher than is needed to prevent anemia, and is an example of a functional dose of a nutrient to help support optimal nerve and brain health.

Coenzyme forms of folic acid (folate as 5-Methyltetrahydrofolic acid) and B12 (methylcobalamin) can make a huge difference in these nutrients working in your body. These are the forms of these nutrients that are ready for your body to put to use. Taking the coenzyme forms is especially important for individuals who have genetic weaknesses in properly activating B12 and folic acid. However, I believe these forms work better for anyone. Individuals should take B12 and folate together, because they work as a nutrient team.