Water Soluble Vitamins
BeriBeri was known to the Chinese 5000 years back. However the fact that it was due to Vitamin B1 deficiency 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 occurs in infants less than 6 months fed exclusively on formula feeds not having thiamine. It is now rare.
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.
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.