Reference from the joint report of FAO/WHO expert consultation on Human Vitamins and Minerals verbatim.
1. Widdowson, E.M., McCance, R.A. & Spray, C.M. 1951. The chemical composition of the Human body. Clin. Sci., 10: 113-125.
2. Forbes, G.B. 1987.Human body composition: growth, aging, nutrition and activity. New York. Springer-Verlag.
3. Schroeder, H.A., Nason, A.P. & Tipton, I.H. 1969. Essential metals in man: magnesium. J. Chronic. Dis., 21: 815-841.
4. Heaton, F.W. 1976. Magnesium in intermediary metabolism. In: Magnesium in Health and Disease. Canatin M., Seelig, M. eds. p 43-55. New York. SP Medical and Scientific Books.
5. Webster, P.O. 1987. Magnesium. Am. J. Clin. Nutr., 45: 1305-1312.
The human body contains about 760 mg of magnesium at birth, approximately 5 g at age 4–5 months, and 25 g when adult (1–3). Of the body’s magnesium, 30–40 percent is found in muscles and soft tissues, 1 percent is found in extracellular fluid, and the remainder is in the skeleton, where it accounts for up to 1 percent of bone ash (4, 5).
6. Waterlow, J.C. 1992. Protein Energy Malnutrition. London, Edwin Arnold.
7. Classen, H.G. 1984. Magnesium and potassium deprivation and supplementation in
animals and man: aspects in view of intestinal absorption. Magnesium, 3: 257-264.
8. Al-Ghamdi, S.M., Cameron, E.C. & Sutton, R.A. 1994. Magnesium deficiency:
pathophysiologic and clinical overview. Am. J. Kidney Dis., 24: 737-754.
Soft tissue magnesium functions as a co-factor of many enzymes involved in energy metabolism, protein synthesis, RNA and DNA synthesis, and maintenance of the electrical potential of nervous tissues and cell membranes. Of particular importance with respect to the pathologic effects of magnesium depletion is the role of this element in regulating potassium fluxes and its involvement in the metabolism of calcium (6–8).
Magnesium depletion depresses both cellular and extracellular potassium and exacerbates the effects of low potassium diets on cellular potassium content. Muscle potassium becomes depleted as magnesium deficiency develops, and tissue repletion of potassium is virtually impossible unless magnesium status is restored to normal. Low plasma calcium develops frequently as magnesium status declines.
9. Breibart, S., Lee, J.S., McCoord, A. & Forbes, G. 1960. Relation of age to radiomagnesium in bone. Proc. Soc. Exp. Biol. Med., 105: 361-363.
It is not clear whether this occurs because parathyroid hormone release is inhibited or, more probably, because of a reduced sensitivity of the bone to parathyroid hormone, thus restricting withdrawal of calcium from the skeletal matrix. Between 50 percent and 60 percent of body magnesium is located within bone, where it is thought to form a surface constituent of the hydroxyapatite (calcium phosphate) mineral component. Initially much of this magnesium is readily exchangeable with serum and therefore represents a moderately accessible magnesium store, which can be drawn on in times of deficiency. However, the proportion of bone magnesium in this exchangeable form declines significantly with increasing age (9).
10. Rude, K.K. & Olerich, M. 1996. Magnesium deficiency: possible role in osteoporosis associated with gluten-sensitive enteropathy. Osteoporos. Int., 6: 453-461.
Significant increases in bone mineral density of the femur have been associated positively with rises in erythrocyte magnesium when the diets of subjects with glutensensitive enteropathy were fortified with magnesium (10). Little is known of other roles for magnesium in skeletal tissues.
No comments:
Post a Comment