Acute vitamin-A deficiencies may be dealt with by injection, but few other cases require this treatment. Vitamins are organic substances which help regulate bodily functions. Acting as co-enzymes, vitamins aid the action of enzymes during the metabolism of dietary nutrients. There are about a dozen major vitamins, a deficiency of any one of which will result in a serious deficiency disease. Vitamins are only required in relatively small quantities, but have a major effect upon the body's reproductive, digestive, nervous and muscular systems.
Vitamins also affect tissue growth and anti-body production.
Plants contain carotene which is converted to true vitamin-A in the body. The B-complex vitamins are water soluble and excesses are excreted in the urine. A deficiency causes pernicious anaemia and neurological symptoms. Deficiencies can occur following malabsorbtion syndrome or as a consequence of severe parasite infestations. The B-complex is just that.