Formation of Vldl Hdl and LDL

In the liver, the constituent lipids of chylomicron remnants are repackaged into HDL and VLDL particles (mainly the latter), which are released into the circulation. There is no direct synthesis of LDL in the liver. VLDL contain high concentrations of triglycerides and moderate concentrations of cholesteryl esters and phospholipids. The triglycerides are removed from VLDL by the action of lipoprotein lipase located on the endothelial surface of blood vessels in extrahe-patic tissues, enabling...

Early studies of nutritionally related diseases

For centuries in the past, certain populations in the world were subjected to the ravages of four particular diseases with well-characterized symptoms these diseases are beriberi, scurvy, pellagra and rickets. Progress in the aetiology of these diseases was hindered by the dogged belief that a disease must be caused by a positive factor, i.e. a microorganism or a toxin. The medical authorities could not envisage that a disease could be caused by a lack of something in the diet. Although the...

Nutritional vitamin deficiency

In countries where diets are unbalanced and inadequate, or where there are particular dietary customs, certain typical disease patterns have been shown to be due to vitamin deficiency. Examples of the most commonly observed diseases are xerophthalmia, rickets, beriberi, pellagra and scurvy, which result from deficiencies of vitamin A, vitamin D, thiamin, niacin and vitamin C, respectively. Deficiency of a single member of the vitamin B group is rare in humans because these vitamins are largely...

Definition and classification of vitamins

Vitamins are a group of organic compounds which are essential in very small amounts for the normal functioning of the body. Thirteen vitamins are recognized in human nutrition and these have been classified, according to their solubility, into two groups. The fat-soluble vitamins are represented by vitamins A, D, E and K also included are the 50 or so carotenoids that possess varying degrees of vitamin A activity. The water-soluble vitamins comprise vitamin C and the members of the vitamin B...