The B vitamins should be called the thinking and feeling nutrients because they nourish the nervous system. Frank deficiencies result in serious neurological conditions such as Wernicke’s encephalopathy. But for the average American eating a normal diet, is this a problem? Yes and no.
While most of us don’t suffer from outright B vitamin deficiency, everyday life imposes many nutritional threats that snatch away these nutrients. Let’s look at how this happens and what you can do to guard yourself.
What are B Vitamins?
While today we know of at least 10 different B vitamins, scientists initially thought this complex of nutrients was just one vitamin. The story begins almost 100 years ago when Eijkman, a Dutch physician living in Java, was watching chickens kept by the local penitentiary. He noticed these birds bore a striking resemblance to his patients suffering from beriberi. Although Eijkman didn’t know it at the time, this condition, characterized in humans by poor memory, irritability, fatigue and other symptoms, is actually caused by thiamin (or B1) deficiency. But the doctor had an inkling that diet might play a part. So he added rice bran to the fowl’s otherwise bleak rations of polished rice table scraps. The experiment worked and the supplemented chickens thrived.
In the decades that followed, more information was elucidated on thiamin and its B vitamin relations: riboflavin (B2), niacin (B3), pantothenic acid (sometimes called B5), vitamin B6 (actually a group of related compounds: pyridoxine, pyridoxal, pyridoxamine and others), B12 (or cyanocobalamin), folic acid and biotin. You’ll notice that some B vitamins are assigned numbers. This is because scientists labeled these compounds in numerical order of discovery. Today we normally refer to the B vitamins by chemical name.
Inositol and choline are sometimes lumped under the B complex title. Less is known about these compounds, and experts don’t always agree on whether they’re true vitamins or not.
A vitamin by definition is a substance that belongs to a group of unrelated organic compounds. Each vitamin is essential for good health (and sometimes life), but you only need a minuscule amount in your food for this purpose. Vitamins vary widely in chemical makeup and physiological function. For the most part, your body can’t manufacture vitamins. Although for the water soluble B vitamins, small amounts of folic acid, niacin and B12 can be synthesized.
The B vitamin clan retain close ties because, like most families, they act alike, sometimes rely on one another and are found in similar foods. They’re so close, in fact, that low intake of one often affects another. This means single B vitamin deficiencies are relatively rare, although deficiency symptoms of one B vitamin may predominate. For this reason, taking large amounts of a single B nutrient may create a vitamin imbalance and snowball into another B vitamin deficiency.
Why Do We Need B Vitamins?
We would literally be lost without B vitamins. Besides memory, these nutrients feed and regulate the brain and nervous system. The brain and its extensive network of nerve fibers and cells, are like a complex computer that instruct us how to react to temperature, pressure, pain and other stimuli. Neurological hookup throughout your body allows organs to function properly. As an added bonus, this complex and not-totally-understood system grants us emotion and thought.
There’s no doubt that the nervous system and brain require their fair share of food and oxygen to grow and thrive. The 100 billion nerve cells that make up the brain and about two percent of the body are very metabolically active. A busy, hungry brain is also sensitive to the ups and downs of nutrients in the blood. Without its own nutritive supply, the brain depends on the rest of the body to feed it.
B vitamins are an important part of the brain’s diet. Many of them help form neurotransmitters, the chemical messengers of the nervous system. Pyridoxal phosphate, a B6 member, is pivotal in the synthesis of the neurotransmitters serotonin, dopamine and gamma-amino butyric acid (GABA) (1). When thiamine is too low, the neurotransmitters glutamate and aspartate also decline. Choline, the vitamin-like cousin of B complex, is needed for acetylcholine.
B Vitamins and Health
Medical journals are brimming with hard-to-pronounce neurological and behavioral conditions that occur when B vitamins are in short supply. Besides emotional, cognitive and behavioral symptoms, inadequate B vitamins can bring on physical complaints too.
While neuropathies, a general term for disorders of the nervous system, can be caused by any number of nutritional deficiencies, B vitamins account for many of them. Pellagra, a niacin-deficient state, and beriberi, due to low thiamin, are probably the most well known of the B deficiency conditions. Beriberi in this country is usually associated with alcoholism, but not always.
The Mayo Medical Center in Rochester, Minnesota reported a case of a 66 year old woman who complained of irritability, loss of appetite, and nausea among other symptoms. Her doctors determined that her sparse diet of fruit cocktail, pop and popsicles, not surprisingly low in thiamin, was responsible. This patient displayed mental changes seen in cerebral beriberi called Wernicke’s encephalopathy. If left untreated, this brain disorder can progress to the more serious Korsakoff’s psychosis. She was given thiamin and eventually recovered (2).
Psychiatric conditions, not typically thought of as B deficient disorders, have also been treated with various B vitamins. Some physicians have given B6 (3), niacin (4) and folate (5) to their schizophrenic patients. Other psychiatric disorders have also been treated with various B vitamins (6).
Most of us, however, are not battling neuropsychiatric illnesses. Still there’s plenty of examples of more common conditions affected by poor B nutrition.
Hungarian scientists discovered that folic acid, alone or with a multivitamin supplement, prevents recurrent neural-tube defect, a type of birth defect. These researchers suggested that all women planning a pregnancy should take folic acid (7). The Center for Disease Control in Atlanta went one step further and advises that all women who “could” become pregnant take this B vitamin (8).
Once a baby is born, the mother must ensure he is properly fed. Thirty-five years ago a proprietary formula, where B6 was inadvertently destroyed during sterilization, caused widespread seizures in infants. The newborns were cured with a B6 supplement, but this situation dramatically shows the impact B vitamins have on the nervous system (1). (By the way, babies who are breast fed by mothers eating a low B6 diet can also have seizures.)
Some neurological childhood conditions also appear to be connected to B vitamins. An interesting study done 20 years ago at Saint Joseph Hospital in Pennsylvania found low serotonin levels in hyperactive children. The investigators fed some of the subjects B6, and observed the neurotransmitter, serotonin, rise appreciably (9). Autism, also called infantile psychosis, has been treated with B6 as well (10).
There are many other circumstances where B vitamins help with neurological problems. Vitamin B6 is used for women suffering from depression due to the birth control pill or premenstrual syndrome (11). It also helps some cases of carpal tunnel syndrome, where the median nerve is painfully compressed within the wrist (11). There’s even a type of rare epilepsy that retreats when B6 is given (12).
Researchers are also analyzing the subtle behavioral and neurological changes that result from mild deficiencies. At one time doctors would admit a vitamin was lacking only with laboratory evidence or well established deficiency symptoms. Experts have discovered that individual tissues, not necessarily the whole body, can be low in a vitamin. They’re also realizing that vitamin requirements might be higher, especially for specific functions, than previously thought. As research continues, the biochemical roles of vitamins are expanding (13).
Slightly low levels of niacin, for instances, may lead to depression, apprehension, hyper-irritability, emotional instability and impairment of recent memory. Marginal thiamin deficiency could, in only five days, cause lassitude (14).
“It is possible that some of the decline in cognitive function associated with aging is preventable or reversible with improved vitamin nutriture especially vitamin B-12, vitamin B6, and folate,” say investigators at the US Department of Agriculture Human Nutrition Research Center on Aging. Some typical psychiatric conditions seen in older citizens, especially depression and even Alzheimer’s, may be due to or exacerbated by poor nutrition. Sadly, low vitamin levels could simmer for months or years without any overt signs (15). Decreased stomach acid (which increases with age), poor eating, chronic illness, medications or institutionalized care may contribute to inadequate B vitamins and other nutrients (16).
Where Have All the B Vitamins Gone?
Modern day lifestyle is not very B vitamin friendly. The manner in which we grow and handle food, our medicines and habits are rough on the fragile members of B complex. Each B vitamin responds differently to its environment with some hardier than others. Here are a few ways the B’s suffer.
This epic begins in the field. Agricultural factors such as the soil, climate, fertilizers used and other growing conditions influence a food’s vitamin content. How ripe or mature a food is when picked determines its nutritional value. Processing foods, like milling flour or grains, curing meats, irradiation, canning, freezing, sulfite use, milk pasteurization and evaporation, also tamper with B vitamin nutriture
Once a food finds its way into your kitchen, it endures another set of B vitamin challenges. Peeling a fruit or vegetable removes much of its goodness (though for highly sprayed produce this is probably wise.) Cooking conditions, which vary widely from cook to cook, rob a few more of the B’s. Finally, the longer you store food, the more you lose. Light is especially hard on nutrients, especially B6 and riboflavin.
Next, the B vitamins must survive the route from your plate to needy spots in your body. Virtually no vitamin is absorbed 100 percent. Even less is absorbed, however, if there’s intestinal damage or low stomach acid. Nutrient status influences how well we use other vitamins and minerals in our food. Absorption of, example B12, decreases with an iron or B6 deficiency.
Some drugs, such as cholestyramine, a cholesterol lowering drug, decreases absorption of folic acid. Cimetidine, for ulcers, dampens digestion and vitamin B12 absorption. Even sodium bicarbonate interferes with vitamin absorption with its acid neutralization. Other B-unfriendly-drugs include sulfasalzine, phenytoin, nitrous oxide, isoniazid, hydralazine, tolazamide, tetracycline and birth control pills (16,17). Alcohol (16) and smoking (18) are harmful too.
In addition to stress, pollution, dieting, illness and injury, less obvious situations requiring higher B complex intake are exercise (16), pregnancy, lactation, and growing children and teens. Chronic, high doses of vitamin C can decrease B12 levels too.
In light of the evidence, it seems we’re all bound for confused and unhappy B deficient lives. Not necessarily so. Knowing B complex’s weaknesses gives you the ability to make good nutritional decisions. Eat as many fresh, raw, whole foods as possible including whole grains, dark green leafy vegetables and dried beans. Follow the macrobiotic principle of choosing foods that are regional and in season. A backyard garden is an ideal way to do this, or visit local farmers. Avoid smoking and alcohol.
If you’re in a B-vitamin-draining situation, such as taking medication (see above or ask your doctor), pregnant, under stress (aren’t we all) or ill, consider supplementing your diet with B complex. Since vitamins and mineral taken in large doses can impact each other, a multiple is best. If you suspect you or a loved one is suffering from the effects of B vitamin deficiency, consult a nutritionally trained physician for a complete work-up. Stay healthy, happy and sound of mind by protecting the B’s in your life.
- Dolphin et al (eds). Vitamin B6: Pyridoxal Phosphate. Toronto: John Wiley & Sons, 1986, chapter 17.
- Tan GH et al. Acute Wernicke’s encephalopathy attributable to pure dietary thiamine deficiency. Mayo Clinic Proceedings 1994;69:849-850.
- Pfeiffer CC, Sohler A, Jenney CH, Iliev V. Treatment of pyroluric schizophrenia (malvaria) with large doses of pyridoxine and a dietary supplement of zinc. Journal of Orthomolecular Psychiatry 1974;3(4):292-300.
- Hoffer A. Vitamin B3 dependent child. Schizophrenia 1971;3:107-113.
- Anon. Folate-responsive homocystinuria and “schizophrenia”. Nutrition Reviews 1982;40(8):242-45.
- DeLiz AJ. Large amounts of nicotinic acid and vitamin B12 in the treatment of apparently irreversible psychotic conditions found in patients with low levels of folic acid. Journal of Orthomolecular Psychiatry. 1979;8(2):58-62.
- Czeizel AE, Dudas I. Prevention of the first occurrence of neural-tube defects by periconceptional vitamin supplementation. The New England Journal of Medicine 1992;327:1832-35.
- Cimons M. US advises folic acid use to reduce birth defects. Los Angeles Times, Tuesday, September 15, 1992: A1 & A17.
- Bhagavan HN, Coleman M, Coursin DB. The effect of pyridoxine hydrochloride on blood serotonin and pyridoxal phosphate contents in hyperactive children. Pediatrics 1975;55: 437-41.
- Martineau J, Barthelemy C, Garreau B, Lelord G. Vitamin B6, magnesium, and combined B6-Mg: therapeutic effects in childhood autism. Biological Psychiatry 1985;20:467-78.
- Brush MG, Bennett T, Hansen K. Pyridoxine in the treatment of premenstrual syndrome: a retrospective survey in 630 patients. The British Journal of Clinical Practice 1988;42:448-52.
- Baumeister FAM, Wieland G, Shin YS, Egger J. Glutamate in pyridoxine-dependent epilepsy: neurotoxic glutamate concentration in the cerebrospinal fluid and its normalization by pyridoxine. Pediatrics 1994;94(3):318-321.
- Machlin LJ. New views on the function and health effects of vitamins (ed). Nutrition 1994;10(6):562.
- Anderson GH. Diet, neurotransmitters and brain function. British Medical Bulletin 1981;37(1):95-100.
- Rosenbewrg IH, Miller JW. Nutritional factors in physical and cognitive functions of elderly people. American Journal of Clinical Nutrition 1992;55:1237S-43S. Quote, pg 1237S.
- Shils ME, Young VR. Modern Nutrition in Health and Disease (7th ed). Philadelphia: Lea & Febiger, 1988, pg 992.
- Morgan BLG. The Food and Drug Interaction Guide. New York: Simon & Schuster, 1986, p 264.
- Piyathilake CJ et al. Local and systemic effects of cigarette smoking on folate and vitamin B12. American Journal of Clinical Nutrition 1994;60:559-566.