Parents want to ensure their children are well fed and eating all the nutrients that are vital for their development. Despite the best efforts to give children adequately wholesome food, however, many young people lack essential nutrients. Among the most essential of these are the B vitamins. Not only children, but also adults and the elderly should take care to consume enough B vitamins.

About B vitamins

The B vitamins are commonly found in plant and animal food sources. They help convert food into energy and form red blood cells.

B vitamins are water-soluble; this means they dissolve in water. Their solubility causes two problems: B vitamins are easily broken down in cooking (meaning their content diminishes in the food) and unable to be stored in the body. Excess B vitamins leave the body through urine. People therefore need to ingest B vitamins continuously.

Eight vitamins make up the B-vitamin group, also known as the B-complex vitamins.

• Vitamin B1 or thiamin

• Vitamin B2 or riboflavin

• Vitamin B3 or niacin

• Vitamin B5 or pantothenic acid

• Vitamin B6 or pyridoxine

• Vitamin B7 or biotin

• Vitamin B9 or folate (known as folic acid in supplements)

• Vitamin B12 or cyanocobalamin

A well-balanced diet will meet dietary requirements for B vitamins if it includes approximately five servings of fruits and vegetables, along with adequate grains per day. Adults over the age of 50 might want to take vitamin supplements in order to avoid a deficiency. Pregnant and breastfeeding women, who require extra folate, should take at least 400 micrograms of folic acid a day throughout their pregnancies and while breastfeeding.

Most other people can obtain enough B vitamins from natural food sources, such as:

• Whole grains: wheat and oats

• Leafy green vegetables

• Beans and peas

• Fish and seafood

• Poultry and meats

• Eggs

• Dairy products

Vitamin B1 (Thiamin): Thiamin is responsible for numerous bodily functions such as nervous system and muscle function and the conversion of glucose to energy.

Dietary sources include whole-meal cereal grains, seeds, legumes (beans and lentils), milk, nuts, oats, yeast, beef, and pork. Excessive consumption of polished (glucose-enriched) rice and flour, alcohol abuse, and an otherwise poor diet result in deficiency of thiamin. Symptoms of a thiamin deficiency include poor limb coordination, fatigue, muscle weakness, confusion, and irritability. Many industrialized countries fortify white rice and flour with thiamin because it is lost during the refining process. Severe thiamin deficiency results in the following conditions:

Wet and Dry Beriberi: In these conditions, the cardiovascular, nervous, muscular, and gastrointestinal systems become afflicted. In wet beriberi, heart abnormalities lead to heart failure. In dry beriberi nerve and muscle abnormalities result in a prickling sensation, leg cramps, and weakened muscles.

Wernicke-Korsakoff Syndrome: This syndrome results from a poor diet and excessive alcohol intake, causing reduced thiamin absorption. Symptoms include involuntary eyeball movement, eye-muscle paralysis, staggering, and mental confusion.

Normally, oral thiamin supplements can correct a deficiency.

Vitamin B2 (Riboflavin): Riboflavin is essential for metabolizing carbohydrates, proteins, and fats; this vitamin also keeps mucus membranes of the eyes and skin healthy.

Dietary sources include whole-grain bread and cereals, milk and dairy products, fish, meat, leafy green vegetables, egg whites, and yeast.

Riboflavin deficiency results from excessive alcohol consumption and a diet lacking milk and dairy products. This deficiency is normally seen along with other B-vitamin deficiencies and includes symptoms such as inflamed tongue, cracks in the corners of the mouth, inflamed eyelids along with sensitivity to light, burning and itching of the eyes, hair-loss, skin rash, and peeling. The deficiency can be corrected by oral intake of supplements in high doses.

Vitamin B3 (Niacin): Niacin, like riboflavin, plays an important role in metabolizing carbohydrates and fat; it also aids the nervous and digestive systems and skin-health maintenance. Unlike other B vitamins, niacin is extremely stable in high heats and does not break down during cooking.

Dietary sources include milk and dairy products, meat, eggs, whole-grain breads and cereals, mushrooms, and protein-rich foods. The body can also convert an amino acid called tryptophan, which is found primarily in dairy products, into niacin if enough niacin is not being consumed.

Niacin deficiency results in a condition called pellagra, which affects the skin, digestive tract, and brain. Pellagra is common in communities where corn is a dietary staple. Pellagra develops because corn is low in niacin and tryptophan. Additionally, consuming alcohol excessively and not taking in enough iron, riboflavin, and pyridoxine (vitamin B6) increases the risk of developing a niacin deficiency.

The main symptoms of niacin deficiency are called the three Ds: dementia, diarrhea, and dermatitis (skin inflammation). Additional symptoms include swollen tongue, loss of appetite, anemia, irritability, mental confusion, weakness, and dizziness. Taking oral supplements can treat the deficiency. At times, doctors prescribe high doses of niacin to lower a patient's cholesterol and lipid levels.

Vitamin B5 (Pantothenic Acid): Pantothenic acid is required for metabolizing carbohydrates, proteins, and fats; it is also essential for growth.

Dietary sources include legumes, broccoli, cabbage, peanuts, whole-grain cereals, milk, eggs, meat, yeast, poultry, and fish. Not much of this vitamin is lost during cooking. Because pantothenic acid exists in a broad range of foods, deficiency is rare. Symptoms of a pantothenic acid deficiency include fatigue, loss of appetite, and intestinal problems.

Vitamin B6 (Pyridoxine): Pyridoxine aids metabolism of carbohydrates, proteins, and fats; it also helps normal nerve functioning as well as formation of red blood cells.

Dietary sources include cereal grains, legumes, green leafy vegetables, potatoes, milk, cheese, eggs, fish, meat, nuts, and fruit.

Pyridoxine deficiency results from excessive alcohol consumption. In women (especially those using an oral birth control), the elderly, and people with thyroid disease the deficiency is more common. Symptoms include insomnia, depression, anemia, cracked corners of the mouth, muscle twitching, confusion, and dermatitis. In infants, pyridoxine deficiency can cause seizures. Doctors sometimes prescribe pyridoxine to treat premenstrual syndrome in women and carpal tunnel syndrome. Patients should follow dosages exactly, as an overdose can result in irreversible nerve damage.

Vitamin B7 (Biotin): Biotin is essential for forming fatty acids and glucose, both of which provide the body energy. Biotin is also involved in amino-acid metabolism.

Dietary sources include cauliflower, peanuts, poultry, egg yolks, mushroom, carrots, bananas, soy flour, and yeast. Biotin is also produced naturally by bacteria in the intestines; because of this, deficiency is rare. When biotin deficiency does occur, symptoms include pale skin, sore tongue, dermatitis, balding, muscle pain, and fatigue.

Vitamin B9 (Folate): Folate is essential for the formation of red blood cells, development of the fetal nervous system, DNA synthesis, and cell growth. Women who are pregnant or might become pregnant should eat a diet rich in folate. Folic acid, a synthetic folate, is sometimes taken as a supplement.

Dietary sources include leafy green vegetables, legumes, seeds, eggs, cereals, citrus fruits, mushroom, yeast, and poultry. "Enriched" is a term given to breads and cereals that have folic acid added to them.

A folate-deficient diet can result in fatigue, weight loss, folate-deficiency anemia, and an increased risk of neural tube defects (such as spina bifida or cleft palate) in the fetuses of pregnant women. Excessive folate intake should be avoided, however, because in high quantities folate can mask a vitamin-B12 (cyanocobalamin) deficiency.

Vitamin B12 (Cyanocobalamin): Cyanocobalamin plays an important role in protecting nerve cells, forming red blood cells, mental capacity, and metabolizing fatty and amino acids. 

Dietary sources include meat, fish, shellfish, dairy products, and other animal sources of food.

Because the human body can store vast amounts of cyanocobalamin, deficiency is rare. Despite this, elderly people and those unable to absorb vitamin B12 might develop the deficiency. Others at risk include vegans and strict vegetarians who might not be getting enough cyanocobalamin in their diets; breastfed babies of vegan mothers might develop pernicious anemia due to lack of intestinal absorption of cyanocobalamin. Symptoms of deficiency include fatigue, lack of appetite, weight loss, anemia, depression, smooth tongue, and nerve degeneration. Cyanocobalamin and folate depend on each other to work properly.