Malnutrition and starvation – general food deprivation due to a number of different causes:
- lack of food
- diseases preventing nutrient absorption eg, cancer
- anorexia and metabolic dysfunction due to organ failure or long term infection, or self inflicted anorexia nervosa and bulimia
- sub-clinical malnutrition from a diet of highly processed junk food, soft drinks, caffeine and alcohol
- obesity – general intake of excess food, with general lack of physical activity
Kwashiorkor – is due to an inadequate intake of utilisable protein, ie. a deficiency of amino acids necessary for protein synthesis. It occurs principally in children shortly after weaning.
Rickets – is a disease of calcium phosphorous metabolism that occurs when infants are weaned onto predominantly cereal diets with insufficient milk to provide calcium and insufficient Vitamin D to aid calcium absorption.
Osteomalacia and osteoporosis –two chronic diseases of the skeleton. Osteolmaliac is due to a deficiency of calcium or Vitamin D or both, which results in failure to deposit calcium and other minerals in the bones and is the adult equivalent of rickets. Osteoporosis is due to a general decrease in calcium content in the bones which tends to occur with age and poor dietary intake of calcium or poor absorption of same.
Scurvy – is a nutritional disease which results from prolonged lack of ascorbic acid from fresh fruits and vegetables, causing a disturbance in the structure of connective tissue and leading to bleeding gums and haemorrhages into the skin.
Beriberi – is due principally to a dietary deficiency of thiamin, which can occur when diets are based heavily on intakes of highly milled rice as occurs in some Asian countries.
Pellagra – is a nutritional disease related to a diet heavily based on maize or corn. The protein of maize is deficient in the amino acid tryptophan, from which the body can make nicotinic acid and although maize actually contains a reasonable supply of nicotinic acid it is in a bound form which can not be absorbed.
Nutritional Anaemias – red blood corpuscles have a life span of about 120 days after which they need to be replaced, for this body requires certain nutrients – the minerals iron, copper and cobalt, Vitamins B12, folacin, ascorbic acid, pyridoxine and protein. Iron deficiency is the most common cause of anaemia, pernicious anaemia is due to lack of vitamin B12 and megaloblastic anaemia is due to lack of folacin, protein and ascorbic acid.
Xerophthalmia, Keratomalacia, Blindness – these are progressive diseases of the eye due to Vitamin A deficiency. The earliest symptom is night blindness and dryness of the eyes and if untreated will eventually lead to total and permanent blindness. Vitamin A must not be taken during pregnancy, and is therefore no longer a component of quality supplements.