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How to “B” Smart

There are eight B vitamins, and they’re all instrumental to the brain.


Ever since they were first “discovered,” the B vitamins—there are eight of them—have been linked to brain function. The first to be identified, thiamine, was recognized by its absence, which turned out to be the cause of devastating nerve damage that afflicted Japanese prisoners in the late 19th century, as the Japanese diet moved away from brown to “polished,” or white, rice. What no one realized was that stripping away the hull of each grain also removed essential nutrients. The discovery of the cause of the disorder, beriberi, garnered a 1929 Nobel Prize—and set in motion the methods scientists use to investigate all vitamins and their role in health.

All of the Bs influence brain function because they each contribute to energy operations in nerve cells. Thiamine, number one among the Bs, has, arguably, the most important role: It enables the body to form adenosine triphosphate (ATP), a mitochondrial molecule that powers every cell of the body and brain. Since the brain uses a disproportionate amount of energy, it is especially thiamine-thirsty. Like the other Bs, thiamine helps convert carbohydrates and fats into fuel. But it also acts as a key regulator for the flow of electrolytes in and out of nerve and muscle cells.

Riboflavin, B2, is the only vitamin that leaves a visible trace—it turns urine bright yellow. As with the other Bs, it’s involved in energy production and body growth, but it’s essential for recycling glutathione, the mother of all disease-preventing antioxidants. It also promotes iron metabolism.

Niacin, B3, is actually a group of related compounds—including nicotinamide and nicotinic acid—and helps in the storage of food and its conversion to fuel. It’s a precursor to enzymes NAD (nicotinamide adenine dinucleotide) and NADP (nicotinamide adenine dinucleotide phosphate), needed in many metabolic reactions and as slayers of free radicals of oxygen.

Pantothenic acid, B5, is used to produce coenzyme A (CoA), fundamental for the body’s handling of fatty acids.

Pyridoxine, B6, is not only important in food-to-fuel actions, notably the breakdown of carbohydrates, it also helps in mood regulation. The body needs it for production of red blood cells and neurotransmitters, especially dopamine, serotonin, and GABA. Recent evidence links B6 deficiency to risk for depression, attention deficit disorder, and inflammatory processes in chronic diseases.

Biotin, B7, is now known to play a notable role in fat and glucose metabolism, although its function was much of a mystery until recently. It’s necessary for producing fats, and among other roles, for making insulin, the hormone that regulates glucose levels in blood and makes glucose available to cells for energy.

Folic acid, B9, is by far the most researched B today. It’s crucial for synthesis of DNA and RNA and for the formation of new cells, which makes it critical at times of rapid cell growth, such as gestation and infancy. It is especially needed for development of the brain and spinal cord. Its full role is still very much under study, but folate deficiency is implicated in the early development of mental disorders like autism, schizophrenia, and depression. It is B9’s job to produce messaging molecules, notably serotonin and dopamine, that allow the nerves to communicate throughout the body. Folate also supports the cardiovascular system, helping to regulate levels of homocysteine, an amino acid implicated in arterial plaque formation.

Cobalamin, B12, is the largest of the B vitamins, not easily absorbed, and like its B brethren, primarily an energy metabolizer. It also supports the cardiovascular system by producing red blood cells and keeping homocysteine levels in check. Because red blood cells are crucial for transporting oxygen and B12 maintains hemoglobin, B12 plays a big role in keeping the brain healthy. With B9, it’s a key factor in DNA production.

Putting Verve in Nerves

The Bs play highly dynamic roles in fuel production and availability. Here's which vitamins you need and why.

B1 Thiamine: Production of ATP, the energy molecule in mitochondria

B2 Riboflavin: Glutathione production

B3 Niacin: Energy metabolism; antioxidant generation

B5 Pantothenic acid: Coenzyme A (CoA) production; fat metabolism

B6 Pyridoxine: Serotonin, dopamine, GABA synthesis; production of hemoglobin, the oxygen transporter

B7 Biotin: Insulin production; glucose and fat metabolism

B9 Folic acid: Serotonin and dopamine production; cardiovascular health; red blood cell production; possibly stem-cell production

B12 Cobalamin: DNA production; cardiovascular health; protection of myelin sheath of nerves

B Cause

  • The B vitamins are now known to be chemically distinct, but they were once thought to be a single entity.
  • Where there's one B vitamin, there are usually others. They tend to work together.
  • The functions of the B vitamins in cells are interlocked; for example, Bs 6, 9, and 12 coregulate homocysteine levels.
  • None of the B vitamins are stored long-term in the body.
  • In addition to being critical factors in brain metabolic processes, the Bs play a role in the maintenance of healthy skin.
  • Thiamine, B1, is often stripped out of foods in processing.
  • Riboflavin, B2, allows the body to make use of pyridoxine, B6.
  • Pantothenic acid, B5, is essential for the body's production of melatonin.
  • Both B6 and B12 contribute to the myelin sheath around nerve cells, which speeds signals through the brain.
  • Folate, B9, takes its name from its common source: leafy vegetables.
  • B12 is named cobalamin because it is the only B vitamin to contain a metal--cobalt.
  • Choline is a half-sister of the Bs, active in metabolism but also integral to the membrane of all cells, including brain cells. And it's a key component of the neurotransmitter acetylcholine, which plays a role in memory.