Vitamin health research

The recognition that vitamin A could be used as a treatment for infections dates to antiquity. Fish liver oils, a potent source of vitamin A, were used as a treatment for infections in Greek and Roman medicine. Experiments in the 1920 s suggested that vitamin A-deficient animals were more susceptible to infections, and Green and Mellanby dubbed vitamin A the anti-infective vitamin in 1928 [5]. At least thirty trials were conducted between 1920 and 1940 which examined the use of vitamin A as a therapy for a wide variety of infections in humans. Although these early trials were encouraging, the emergence of sulfa antibiotics in the late 1930 s and the disappearance of malnutrition in industrialized countries led to a caesura in research on vitamin A as an anti-infective therapy. The description of an association between mild vitamin A deficiency and increased child mortality renewed interest in vitamin A [6], and further controlled clinical trials were conducted in the 1980 s which provided more definitive evidence for vitamin A as a public health intervention [2]. 

The possibility that vitamins might have physiological functions beyond the prevention of deficiency diseases was first recognized in 1955 with the finding (8) that niacin can affect semm cholesterol levels in humans. An explosion of research (9—11) in the intervening years has been aimed at estabUshing optimal vitamin levels and anticipating the health consequences. 

In the Unites States, the daily intake of 3-carotene is around 2 mg/day Several epidemiological studies have reported that consumption of carotenoid-rich foods is associated with reduced risks of certain chronic diseases such as cancers, cardiovascular disease, and age-related macular degeneration. These preventive effects of carotenoids may be related to their major function as vitamin A precursors and/or their actions as antioxidants, modulators of the immune response, and inducers of gap-junction communications. Not all carotenoids exert similar protective effects against specific diseases. By reason of the potential use of carotenoids as natural food colorants and/or for their health-promoting effects, research has focused on better understanding how they are absorbed by and metabolized in the human body. 

Health benefits — Research reports indicate that natural (3-carotene possesses numerous benefits for the human body and consistently supports the use of (3-carotene as part of the human diet. The human body converts (3-carotene to vitamin A via body tissues as opposed to the liver, hence avoiding a build-up of toxins in the liver. Vitamin A is essential for the human body in that it assists the immune system and helps battle eye diseases such as cataracts and night blindness, various skin ailments such as acne, signs of aging, and various forms of cancer. 

United States Public Health Service, the National Science Foundation, the Office of Naval Research, the Mental Health Association, the National Multiple Sclerosis Society, the Williams-Waterman Fund of Research Foundation Inc., and the National Vitamin Foundation. 

A healthy diet with proper nutrition is essential for maintaining good overall health. Since the discovery of vitamins earlier in this century, people have routinely been taking vitamin supplements for this purpose. The Recommended Dietary Allowance (RDA) is a frequently used nutritional standard for maintaining optimal health. The RDA specifies the recommended amount of a number of nutrients for people in different age and sex groups. The National Research Council s Committee on Diet and Health has proposed a definition of the RDA to be that amount of a nutrient which meets the needs of 98% of the population. 

Research vitamins C, E, alpha- and beta-carotenes, and folic acid. How do they affect our health What fruits and vegetables contain these vitamins ... 

Legitimate clinical research is being conducted with vitamins in many areas including heart disease, ophthal-mological disease, neurocognitive function, and dermatological diseases. It is important for physicians to be aware of scientific information that either supports or refutes a role for vitamins in the maintenance of health or in the avoidance of disease. 

In the meantime, it is clear that intake of adequate amounts of vitamins and minerals may have a major effect on health, and the costs and risks of a daily multivitamin/mineralpill are low.49 More research in this area, as well as efforts to improve diets, should be high priorities for public policy. 

T During the first third of the twentieth century, a major focus of research in physiological chemistry was the identification of vitamins, compounds that are essential to the health of humans and other vertebrates but cannot be synthesized by these animals and must therefore be obtained in the diet. Early nutritional... 

The fortification of these milk products with vitamin A is endorsed by the American Medical Association, with the concurrence of the Food and Nutrition Board, National Academy of Sciences, National Research Council and the Expert Panel on Food Safety and Nutrition of the Institute of Food Technologists (AMA 1982). The fortification of dried skim milk with vitamin A is viewed by the World Health Organization and the Food and Agricultural Organization (WHO 1977) as an important measure to combat vitamin A deficiency in developing countries, where 20,000 to 100,000 children yearly develop blindness from a lack of vitamin A in their diets (DeLuca et al. 1979). 

Deficiency syndromes of Zn, Cu, Cr, Se and Mo have occurred in patients on total parenteral nutrition (TPN). There is still much research to be done in assessing the nutritional status of many elements and understanding their metabolism, so that normal dietary intake may be supplemented for health benefits. Table 2 is a summary of the amounts required, the functions and the nutritional (usually dietary) imbalances in humans, where known, of the essential trace elements.31-33 (Note that this summary does not attempt to include imbalances related to environmental toxicology and occupational hazards.) Several trace elements have important functions in the immune system. Some are associated with nucleic acid. Others have structural roles, such as Si in cartilage, F and Zn in bone. They may be parts of vitamins, such as Co in vitamin B12, or hormones, such as iodine in thyroid hormones, Zn and Cr have a role in the synthesis and action of insulin.31-33... 

United States Congress passes Dietary Supplement Health and Education Act, which expressly defines a dietary supplement as a vitamin, a mineral, an herb or other botanical, an amino acid, or any other dietary substance. This law prohibits claims that herbs can treat diseases or disorders, but it allows more general health claims about the effect of herbs on the structure or function of the body or about the well-being they induce. Under this law, the FDA bears the burden of having to prove an herbal is unsafe before restricting its use. This law also establishes the Office of Dietary Supplements within the National Institutes of Health to promote and compile research on dietary supplements. 

Abbreviations CA, carotid atherosclerosis CPIHD, Caerphilly Prospective Ischemic Heart Disease EVCS, Elderly Vitamin C Status IWHS-D, Lowa Women s Health Study MGH, Mortality in a Geriatric Hospital MRCT Medical Research Council Trial NAHNES I, National Health and Nutrition Examination Survey PSCHD, Prospective Study of vitamin C in Coronary Heart Disease SOP Supplementation... 

The discovery, isolation and final synthesis of a whole group of new compounds essential to health in a balanced diet was another triumph of the chemist. These compounds called vitamins A, Ba or G, C, D, E, K, and several others closely associated with vitamin Ba, such as niacin, pantothenic acid, inositol, para-amino benzoic acid, choline, pyndoxine (Be), biotin (H), folic acid and Bn, prevent deficiency diseases such as xerophthalmia (an eye disease), beriberi, pellagra, scurvy, rickets, sterility (in rats), excessive bleeding and so forth. Professors Elmer V. McCollum and Herbert M. Evans, and Joseph Goldberger were among the early American pioneers in this field of research. Drugs, anaesthetics, and medicines like procaine, cyclopropane, dramamme, ephedrine, aspirin, phenace-tin, urotropin, veronal, quinine, and strychnine have been synthesized to alleviate the pains of mankind. The essential... 

Carr AC, Zhu BZ, and Frei B (2000) Potential antiatherogenic mechanisms of ascorbate (vitamin C) and alpha-tocopherol (vitamin E). Circulation Research 87,349-54. Diplock AT (2001) Antioxidants, nutrition and health. In Food and Nutritional Supplements Their Role in Health and Disease, IK Ransley, IK Donnelly, and NWRead (eds.), pp. 65-80. Berlin Springer. 

Parks E and Trader MG (2000) Mechanisms of vitamin E regulation research over the past decade and focus on the future. Antioxidants and Redox Signaling 2,405-12. Rayman M (2000) The importance of selenium to human health. Lancet 356, 233-41. Rlcciarelli R, Zingg JM, andAzziA(2001) Vitamin E protective role of a Janus molecule. FASEB Journal 15,2314-25. 

---