Effects of calcium, fluoride and magnesium supplementations on tissue mineralization in calcium- and magnesium-deficient rats.

There is considerable uncertainty about the interrelated effects of calcium (Ca), magnesium (Mg) and fluoride (F) on hypocalcification of the skeleton and Ca accumulation in vital soft tissues. This paper describes experiments with rats fed a diet deficient in Ca and Mg, the latter deficiency being accentuated by a low potassium content. For different groups the drinking water was supplemented with Ca, Mg, F, Ca + F or Mg + F; Ca and F were supplied as chemically compatible compounds. At the end of the 54-d experiment, plasma Ca was strongly reduced in the Ca-deficient groups. Plasma Mg was reduced particularly in the test groups supplied with Ca, without any influence of F supply or varying plasma F. Ca accumulation was much more pronounced in the kidneys than in the heart or aorta, but was mitigated by both Mg and F supplementation. Bone mineralization disturbance due to the dietary imbalance was preventable only by Ca or Ca + F supplementation, and was less in alveolar bone than in femur. However, the Ca supplement was associated with the highest aorta and heart Ca contents, and Ca + F was associated with marked renal Ca accumulation; adequate Mg supply may be essential with Ca + F administration against osteoporosis.