Riboflavin B2 Niacin B3

Riboflavin (Vitamin B 2)

This is another Vitamin of the B group. It is water soluble. The rich sources of this vitamin are, eggs, meat, milk and other dairy products, fish, green vegetables, yeast etc.

This vitamin works in the cells mainly in energy transport, dehydrogenation, oxidation and electron transport mechanisms.

Deficiency of this vitamin is common in cases  where food intake is less

  • starvation,
  • after natural and man-made calamities,
  • in anorexia nervosa
  • and diseases of intestines where absorption is limited,

Deficiency suggests relatively recent problem as the vitamin is not stored for long in the body.

The daily requirement is about 1.3 mg in men and 1.1 mg in women.

Deficiency causes non-specific signs and symptoms. The common manifestations are

  • Redness of throat, 
  • Sores at angles of the mouth, 
  • Redness of inner lining of cheeks, 
  • Dermatitis with excess sebum production, 
  • Anemia etc.

Treatment consists of replacement of the hormone.

Niacin (Vitamin B 3)

The symptoms of Niacin deficiency were first described in 18th century. This disease was common in people partaking a diet of corn. This vitamin is found in meats, eggs, legumes, yeast etc. It can also be made from the amino acid tryptophan.

This vitamin is also a cofactor in enzyme activities in cells and is required for oxidation and reduction processes.

About 18 mg of niacin is required daily by man and 16 mg by woman.

Deficiency is seen in starvation states as in Vit B2 def, in diseases of the intestines.

It is also caused by anti TB drug Isoniazid. In some cases of cancers, the requirement is high as nutrition is consumed by cancer cells.

The symptoms of deficiency are 3 D’s i.e.

  • Dermatitis, it is typically photosensitive and looks like crazy pavement
  • Diarrhoea
  • Dementia ( or loss of various cognitive functions of the brain)

Very high doses of this vitamin (in gms/day) decrease cholesterol levels and slow atherosclerosis.

Deficiency states are treated by replacement of the vitamin by tablets.

Water Soluble Vitamins

Water Soluble Vitamins


BeriBeri was known to the Chinese 5000 years back. However the fact that it was due to Vitamin Bdeficiency was only known in 1926. This vitamin is found in nuts, legumes, yeast and rice (unpolished). It is not found in fruits, milk or vegetables. The meagre quantities found in these can be destroyed by cooking as well.

This vitamin is required for the metabolism of carbohydrates and proteins in the body. It forms part of a chemical required for enzymatic activity.

The requirement for man and woman is slightly more than 1 mg /day. A pregnant woman may require about one and half times of this.

Severe deficiency of this vitamin can cause the following diseases:

Infantile beriberi

Adult beriberi

Wernicke-Korsakoff syndrome

Leigh disease

Infantile beriberi occurs in infants less than 6 months fed exclusively on formula feeds not having thiamine. It is now rare.

Adult Beriberi:

Dry beriberi usually causes nervous system disorder. Wet beriberi causes swelling of feet, breathlessness, enlargement of the heart and high output heart failure.

Wernicke’s disease causes unsteady walk, nystagmus ( rhythmic involuntary eye oscillations), paralysis of eye muscles etc. Korsakoff’s on the other hand results in short-term memory loss. Confabulations (making up stories) often occurs when facts are not remembered and this may be perceived as madness.

Leigh’s disease means a type of chronic nervous system disorder due to thiamine deficiency.

Deficiency can occur in hospitalised patients in ICUs and wards if vitamins are not supplemented, patients on intravenous feeds, after surgery for obesity and most often in alcoholics or situation of famine, starvation etc. Diagnosis is made by blood tests and the vitamin can be replaced easily.

Folic acid

It is required in small quantities. It has a role in the formation of nucleic acids. Deficiency can lead to a type of anemia called megaloblastic anemia due to the large size of RBC precursors in bone marrow and larger size of RBCs.

This vitamin is present in green and leafy vegetable, a variety of fruits, grains, cereals, nonvegetarian foods like meat etc. In nature, this vitamin is present as folate. The synthetic form provided in tablets or syrup consists of folic acid.

Deficiency can be seen where cell division is increased as in pregnancy.

Benefits of supplementing folic acid in the diet.

In a pregnant woman, supplementing folic acid by 150 to 250 micrograms daily results in lower incidence of neural tube defects. This is important since neural tube defects in children can cause a life of paralysis.

Supplementation can also reduce the risk of certain type of cancers, age-related deafness and high blood pressure.

If a person has high levels of homocysteine in the blood, he or she is more prone to heart attacks and strokes. Folic acid and cobalamins may reduce homocysteine levels.

Higher doses in a non-deficient population may not be altogether safe. Western countries fortify grains with folic acid to reduce the incidence of deficiency. Deficiency can be prevented by taking a large variety of foods, fruits etc.