Calcium absorption supplements

Vitamins A, D, and E are required by mminants and, therefore, their supplementation is sometimes necessary. Vitamin A [68-26-8] is important in maintaining proper vision, maintenance and growth of squamous epitheHal ceUs, and bone growth (23). Vitamin D [1406-16-2] is most important for maintaining proper calcium absorption from the small intestine. It also aids in mobilizing calcium from bones and in optimizing absorption of phosphoms from the small intestine (23). Supplementation of vitamins A and D at their minimum daily requirement is recommended because feedstuffs are highly variable in their content of these vitamins. 

A number of factors can limit calcium absorption, and special consideration must be given to calcium dosing to maximize absorption. Large amounts of calcium taken at once cannot be absorbed. Supplement doses should be limited to 500 to 600 mg of elemental calcium per dose. Calcium intake greater than 2500 mg/day should be avoided due to increased risk of toxicity, including hypercalciuria and hypercalcemia. 

Supplemental vitamin D maximizes intestinal calcium absorption and has been shown to increase BMD it may also reduce fractures. 

Dietary phosphorus also affects calcium metabolism. Polyphosphate decreases calcium absorption in young men while orthophosphate supplement does not (26J. However, in the rat all forms of phosphate decrease calcium absorption about equally (31). However, widely divergent dietary calcium phosphorus ratios do not seem to affect calcium utilization by people as long as there is adequate phosphorus intake (32). In general phosphorus stimulates calcium retention in man (3277... 

Based on limited epidemiologic evidence, fluoride supplements, with or without calcium, estrogen and vitamin D, are used by clinicians for the treatment of osteoporosis. However, knowledge of the effects of fluoride on calcium and phosphorus metabolism in normal animals is limited although Spencer et al. (32) reported that ingestion of fluoride by three osteoporotic men did not affect calcium absorption but caused a decrease in urinary excretion. Moreover, there is a need to determine the long-term effects of fluoride treatment on bone strength and on soft tissues ( ). 

Table I shows that the addition of 140 mg of zinc as zinc sulfate per day, during a low calcium Intake of 230 mg/day, decreased the urinary calcium, Increased the fecal calcium and the calcium balance remained unchanged. In nine patients studied during a low calcium Intake, the Intestinal absorption of calcium decreased significantly during the high zinc Intake, the absorption values averaging 61 + 6,6% In the control study and 39 + 4,6% during zinc supplementation, However, the decrease In calcium absorption was abolished...

Yuan, Y.V. and Kitts, D.D. 1991. Confirmation of calcium absorption and femoral utilization in spontaneously hypertensive rats fed casein phosphopeptide supplemented diets. Nutr. Res. 11, 1257-1272. 

In Japan, where mineral deficiency can be a nutritional problem, the beneficial effects of fructooligosaccharides on calcium absorption have been recognized in the labeling on dietary supplements since 1999 (Hidaka et al., 2001). 

Calcium has long been implicated as a dietary factor which inhibits the absorption of manganese. Since manganese is better absorbed in the oxidized (+2) than in the reduced state (+3 or +4), any factor which increases gastrointestinal tract pH (increases alkalinity) would be expected to inhibit manganese utilization. Calcium carbonate, a commonly used antacid by humans as well as a calcium nutrient supplement, has been found to have a greater adverse effect on apparent manganese absorption in humans than does milk. 

Comparative effects of calcium lactate and milk on apparent manganese utilization by humans are shown on Table II (7). In this study, 10 adult human subjects were fed 900 mg calcium from milk or 916 mg of calcium from calcium lactate/subject/day. Calcium provided by the basal diet was maintained constant. The increase in fecal manganese excretion with the calcium lactate supplemented diet in comparison to values when milk was the supplemental manganese source suggests that calcium supplied by milk had a lesser adverse effect on manganese absorption than did that from calcium lactate (Table II). 

Food fortification has almost completely eliminated rickets in the United States. For those who cannot drink fortified milk and cannot go outside, supplements of vitamin D pills should be considered. In some elderly persons, a 400 lU supplement may not be enough to support normal calcium absorption by the gut, and daily doses of 10,000 lU per day may be needed. 

Sargent JD, Dalton MA, O Connor GT, Olmstead EM, Klein RZ. Randomized trial of calcium glycerophosphate-supplemented infant formula to prevent lead absorption. Am J Clin Nutr 1999 69(6) 1224-30. 

The measurement of calcium absorption is of interest to those studying the availability of the calcium in various foods or supplements. The quantity and availability of food calcium are concerns in the prevention of osteoporosis. Calcium absorption is also of interest to those studying the interactions between different components of food and their influence on calcium absorption. Measurement of either fecal or urinary Ca can indicate the extent of absorption, but some fine-tuning is needed to yield an accurate picture, as described in what follows. The radioactive calcium can be supplied as calcium-45 or calcium-47. Where tire absorption of food Ca is of interest, ttie study can be run most accurately by using food containing naturally labeled calcium, that is, foods grown or animals raised in the presence of radioactive calcium. A less accurate picture can be attained by mixing radioactive calcium with the food, that is, with the plant or animal product. 

Postprandial glucose-dependent insulinotropic polypeptide (GIP) levels were lowered in a guar-gum-supplemented meal (Morgan et al., 1990) and may contribute to lower insulin levels. Guar delays intestinal calcium absorption in humans (Gulliford et al., 1988b). The decrease in pancreatic amylase release may simply be a result of diminished insular-exocrine axis. 

With calcium stone disease, magnesium is an inhibitor of stone growth. Magnesium forms complexes with oxalate that are more soluble than calcium oxalate. Increased urinary magnesium therefore inhibits stone formation. Administration of magnesium has been shown to reduce enteral calcium absorption and has been proposed as a treatment for idiopathic hypercalciuric stone formers. However, oral magnesium supplementation may have unpleasant side effects and a positive benefit in terms of reducing stone recurrence has not been demonstrated. ... 

When the recommended daily allowance (RDA) for calcium is not met by the diet is (particularly in women), supplementation in the form of calcium salts is recommended. Calcium salts vary widely in calcium content by weight, calcium gluconate has 9%, calcium lactate has 13%, and calcium carbonate has 40% calcium. Absorption of calcium from salts may vary calcium carbonate is the most poorly absorbed. Bone meal and dolomite are not recommended sources of calcium, since they may contain lead, arsenic, mercury, and other toxic metals. A potential complication of excessive calcium intake is formation of urinary tract stones this risk may be reduced by ample fluid intake. 

Administration. Most children and adults do not ingest sufficient dietary calcium and require supplements (see Tables 88-5 and 88-6). Individuals with certain characteristics or conditions—such as lactose intolerance nondairy vegetarian diet malnutrition low-fat diets and glucocorticoid, antiresorptive, or parathyroid therapy—also require evaluation for calcium supplementation. To ensure adequate calcium absorption, 25(OH) vitamin D concentrations should be maintained in the normal range." ... 

Mi, S. et al., Study on calcium absorptivity in calcium supplements evaluated by 41Ca labeled calcium pool of osteoporotic rats, Acta Nutrim. Sin., 30( 1), 39, 2008. 

The recommended daily dietary allowance of calcium is 1200 mg. Calcium carbonate is an inexpensive source of calcium and useful as a dietary supplement as long as it is taken along with vitamin D, which is essential to calcium absorption. How many grams of calcium carbonate must an individual take per day to provide for his/her recommended daily allowance of calcium ... 

Tryfonidou, M.A., Stevenhagen, J.J., van den Bemd, G.J., et al 2002. Moderate cholecalciferol supplementation depresses intestinal calcium absorption in growing dogs. /. Nutr. 132 3363-8. 

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