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For the most part, vitamins are obtained from the diet, but some are acquired by other means: for example, microorganisms in the gut flora produce vitamin K and biotin; and one form of vitamin D is synthesized in skin cells when they are exposed to a certain wavelength of ultraviolet light present in sunlight.
Some "minerals" are essential for life, but most are not. [1] [2] [3] Minerals are one of the four groups of essential nutrients; the others are vitamins, essential fatty acids, and essential amino acids. [4] The five major minerals in the human body are calcium, phosphorus, potassium, sodium, and magnesium. [2]
Most of the elements needed for life are relatively common in the Earth's crust. Aluminium , the third most common element in the Earth's crust (after oxygen and silicon ), serves no function in living cells, but is toxic in large amounts, depending on its physical and chemical forms and magnitude, duration, frequency of exposure, and how it ...
Vitamin B complex. Vitamin B 1 (thiamin) Vitamin B 2 (riboflavin) Vitamin B 3 (niacin) Vitamin B 5 (pantothenic acid) Vitamin B 6 group: Pyridoxine; Pyridoxal-5-Phosphate; Pyridoxamine; Vitamin B 7 (biotin) Vitamin B 9 (folate) Vitamin B 12 (cobalamin) Choline; Vitamin A (e.g. retinol (see also - provitamin A carotenoids)) Vitamin C (Ascorbic ...
Furthermore, depending on the location of the double-bond in the fatty acid chain, unsaturated fatty acids are classified as omega-3 or omega-6 fatty acids. Trans fats are a type of unsaturated fat with trans -isomer bonds; these are rare in nature and in foods from natural sources; they are typically created in an industrial process called ...
Vitamins occur in a variety of related forms known as vitamers. The vitamers of a given vitamin perform the functions of that vitamin and prevent symptoms of deficiency of that vitamin. Vitamins are those essential organic molecules that are not classified as amino acids or fatty acids.
Macronutrients are defined as a class of chemical compounds which humans consume in relatively large quantities compared to vitamins and minerals which provide humans with energy. Fat has a food energy content of 38 kilojoules per gram (9 kilocalories per gram) proteins and carbohydrates 17 kJ/g (4 kcal/g).
Vitamin A deficiency is a major factor in causing blindness worldwide, particularly among children. [17] Global vitamin A supplementation efforts have targeted 103 priority countries. In 1999, 16 percent of children in these countries received two annual doses of vitamin A. By 2007, the rate increased to 62 percent. [18]