Calcium nutritional

A. D. Rovira, Root excretions in relation to the rhizosphcre effect IV. Influence of plant species, age of plant, light, temperature and calcium nutrition on exudation. Plant Soil 11 55 (1959). 

Serum calcium levels were depressed with the feeding of 18 to 100 g of wheat bran to human subjects in the study by Heaton and Pomare (10) but were unaffected by the feeding of approximately 20 g of wheat fiber in the study by Jenkins et al. (19). Since blood serum calcium levels tend to be resistant to change except under conditions of severe calcium deficiency, measurement of blood serum calcium levels is probably not sufficiently sensitive to indicate change in calcium nutritional status in short-term feeding studies. 

Albanese, A. A. 1983. Calcium nutrition throughout the life cycle. Bibl. Nutr. Dieta 33, 80-99. 

Adding limestone to soils to correct soil acidity and to supplement available calcium will, of course, indirectly affect human and calcium nutrition, but this is a difficult quantity in measure. 

Adequate calcium nutrition during childhood and adolescence is thought to bean important deterrent to osteoporosis in later life. A one-year study of 149 girls (8 years old) revealed the effects of consuming a typical diet (900 mg Ca/day) or a diet supplemented with an additional 850 mg Ca/day Bonjour el al, 1997). The Ca supplement was supplied by specially prepared biscuits, juices, and candy bars (rather thar pills) to assure compliance. To view some of the data, the density at the femoral diaphysis increased by 5% (unsupplemented) and by 6% (plus calcium) during the 1-ycar period. The density at the lumbar spine increased by 4% (unsupplemented) and by 4% (plus calcium). The data dernonstrated a dear and definite increase in bone density at some sites, but not at others. This study, as well as others Johnston et al., 1992), tend to show that caicium supplements to children can benefit bones of the appendicular skeleton, but not the axial skeleton. The appendicular skeleton includes the pelvis, arm bones, and leg bones. The axial skeleton includes the skull, vertebra, ribs, and sternum. 

The RDA for calcium in adults over the age of 24 is 0.8 g. The RDA for women during pregnancy and lactation is 1.2 g. The increased level of 1.2 g is required to supply the fetus with the 30 g of calcium present in the newborn and to provide the 0.24 g of calcium secreted in the milk each day. The RDA for persons from 11 to 24 years of age is 1.2 g the RDAs for children (0.8 g) and infants (0.6 g) are lower. Eggs supply about 30% of dietary calcium and 30% of dietary phosphate for the overall population in the United States. Meat, poultry, and fish supply 20-25% of our phosphate, but only 10% of our calcium. Milk and dairy products supply 20-25% of our phosphate, and 50% of our calcium (Calvo and Park, 1996). A dietary deficiency in calcium is quite rare, though calcium nutrition receives much attention because of mainstream health concerns related to calcium, such as osteoporosis, hypercalcemia, and hypocalcemia. 

Its inherent toxicity and that of its compounds resembles that of calcium. The state of calcium nutrition of exposed individuals is a major determinant of toxicity. The radioactive isotope, when ingested or inhaled, is processed by the body and resides in bones. Strontium ionizes molecules in the body by the emission of beta particles. It increases the risk of cancer. 

In general, milk and dairy products (particularly Swiss-type cheeses), certain fruits (kiwi, oranges) and vegetables (broccoli, dried beans) as well as processed food such as chocolate exceed others such as meat, poultry or pasta in their relevance for optimal calcium nutrition (Tables 2.3-2 and 2.3-3). Since consumption of mineral water, which can contain relatively high amounts of calcium (Table 2.3-2), is increasing in industrialized countries, it becomes more and more important as a calcium source. 

There is increasing evidence from epidemiological studies that some of the most frequent human malignancies such as breast (Favero etal. 1998, Lipkin and Newmark 1999, Yang et al. 2000, Grant 2002), prostate (Hayes et al. 1999), and particularly colorectal cancer are associated with poor calcium nutrition (Garland et al. 1985, 1991, Lipkin et al. 1991, Martinez and Willet 1998). A... 

Recker RR, Hinders S, Davies KM, Heaney RP, Stegman MR, Lappe JM and Kimmel DB (1996) Correcting calcium nutritional deficiency prevents spine fractures in elderly women. J Bone Miner Res 11 1961-1966. 

DeHayes, D.H., Schaberg, P.G., Hawley, G.J. and Strimbeck, G.R. (1999). Acid rain impacts calcium nutrition and forest health. BioScience, 49, 789-800. 

In addition to its role in bone mineral, calcium has a major function in metabolic regulation, nerve conduction and muscle contraction. Calcium nutrition is discussed in section 11.15.1. 

Murray TM. Prevention and management of osteoporosis consensus statements from the Scientific Advisory Board of the Osteoporosis Society of Canada. 4. Calcium nutrition and osteoporosis. CMAJ 1996 155 935-939. 

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