Vitamins and Nutrition

Vitamin D is not found in milk but obtained from early morning Sun, cod liver oil, shark liver oil, Pilchard, Herring. Rest all are found in the milk.

Vitamin A is an Il-cis-retinal, the lipid prosthetic group of the protein opsin in visual purple. Its defficiency affects all tissues, but the eyes are most readily affected.

Goitre is a condition caused by an enlargement of the thyroid gland, which is frequently associated with iodine deficiency.

Respiration is the oxidation process in which reduced biomolecules like carbohydrates, fats, proteins etc are oxidised to release energy, which can be used for cellular processes. Fats are most reduced biomolecules and their oxidation releases maximum amount of energy. The energy released in oxidation of one gram of fat is twice the energy released in oxidation of one gram of carbohydrate. Hence, carbohydrates are used as an energy reserve biomolecules in living systems.

Vitamin C (ascorbic acid) is known as the antiscorbutic vitamin because it prevents scurvy.

Vitamin K is essential for blood clotting. Beri-beri is caused by a deficiency of Vitamin B1 (thiamine), not Vitamin K.

Vit B & C are water-soluble. Vit K is fat-soluble required for the formation of many clotting factor-like prothrombin. Vit A is also fat-soluble.

Carbohydrates are the primary fuel used in cellular metabolism. Excess carbohydrates are stored as glycogen and fats. The fats are a very concentrated source of energy. One gram of fat provides 8.8 kcal of energy as against 4.2 kcal provided by one gram of carbohydrate.

Fats are energy dense, providing approximately 9 kcal/g (often cited as 9.3 kcal/g), whereas carbohydrates and proteins provide approximately 4 kcal/g.

The vitamins act as part of coenzymes, small molecules that combine with an enzyme to make it active.

FAD also is known as Flavin Adenine Dinucleotide. It is a redox-active co-enzyme associated with various proteins. Riboflavin is the precursor of FAD.

On oxidation of 1gm of fat energy yield is 9.3 cal. For carbohydrate and proteins, the energy value is roughly around 4 cal. Vitamins are not energy yielding compounds.

Vitamin A is fat-soluble and its deficiency causes night blindness. Vitamin K is also fat-soluble, but its deficiency is related to blood clotting issues, not beri-beri.

Steroids like cholesterol are crystallisable lipids having four hydrocarbon rings (phenanthrene, consisting of three cyclohexane and one cyclopentane) and a long hydrocarbon side chain. Fatty acids are absent. Sterols are precursors of steroid hormone and vitamin D. They are essential for plant growth and flowering. Cholesterol forms bile salts and hence, essential for absorption of fatty acids.