The greatest source of thiamin is in unrefined grains or starchy roots and tubers. However, industrial processing such as polishing of the rice grain removes the thiamin. Other sources include liver, kidney, pork, nuts and pulses. However, the greatest dietary source in the Western world is via fortified breakfast cereals. Thiamin is absorbed both actively […]
Found in dairy products, meat, fish and some green vegetables, riboflavin plays a role in the metabolism of other nutrients (such as the conversion of tryptophan to niacin or that of folic acid to its active form 5N-MTHF). Clinical deficiency in children causes growth retardation, skin rashes around mucous membranes as they meet the skin, […]
Niacin is found in food in the form of nicotinic acid and the provitamin tryptophan (an amino acid). It is found in meat in both forms and also in cereals as niacytin (which has a lower bioavailability). Like thiamin, niacin is required as a cofactor in the metabolism of carbohydrate to produce energy. Deficiency results […]
While folate is widely distributed across many food sources, there is no one particularly good source (except liver). Fresh vegetables provide folate but high levels must be consumed and cooking losses minimised. Adequate folate status in women is essential pre-conception and during the first 12 weeks of foetal development to prevent neural tube defects, which […]
A diet containing some fat is required for the absorption of these vitamins. They are less likely to be lost on cooking than water soluble vitamins but are more likely to build up to toxic levels as they are not excreted from the body in the urine, like water soluble vitamins.
Vitamin K is found in plant foods especially leafy green vegetables and vegetable oils. It is thought to play a role in healthy bone development, as deficiency may lead to bone disease. Its deficiency is also responsible for a haemorrhagic disease in newborn infants. Routine supplementation at birth is recommended.
Vitamin E is a powerful antioxidant that helps to protect against oxidative damage in the body caused by reactive oxygen species, which themselves are a natural by-product of many metabolic reactions and exercise but may be exacerbated by smoking, poor diets and polluted atmospheres. Vitamin E plays a role in protecting polyunsaturated fats in the […]
Vitamin A has two major forms of biological significance – the animal based retinol, found in liver, dairy products and oily fish; and the plant derived ß-carotene, found in orange and dark green vegetables and palm oil (the latter have a lower potency than animal derived vitamin A). Vitamin A is absorbed in the small […]
Electrolytes Sodium, potassium and chloride ions are essential to the regulation of water balance within the body. Deficiency Deficiency of sodium, chloride and water, as seen with gastrointestinal diseases (vomiting, diarrhoea), renal (kidney) failure or other renal losses, excessive sweating or loss via burns or dialysis can lead to characteristic symptoms of dehydration – physical […]
Zinc is an essential mineral, required for normal growth of animals and humans. It is a constituent of certain enzymes and acts to stabilise cell membranes. In this way, it plays a role in DNA synthesis, protein digestion and synthesis, carbohydrate metabolism, oxygen transport and protection against free radical damage. Zinc deficiency is difficult to […]
