Explain about the Dietary Calcium Requirements?

There are variations in the amount of calcium recommended by different advisory groups. This is mainly due to the different criteria used as the basis for estimating requirements. The factorial approach is the most common one for determining the calcium needs. In this approach, estimates of how much calcium is deposited in the body on a daily basis are made for infants, children and adolescents and for each group and this is added to the endogenous' calcium losses through different routes.

The total of this is converted to dietary calcium by using the fractional absorption rates observed at different life stages. A recent refinement involves the use of mathematical modelling of experimental data from balance studies to estimate the optimal calcium intakes at or above which calcium retention is maximal or desirable. Another approach is to estimate the optimal calcium intake for bone health, in terms of reduced risk of osteoporosis in later life. Lack of quantitative data in support of this approach is a constraint in using it widely, Calcium requirements have been measured by long-term balance studies. With respect to the desirable intake of phosphorus, it is suggested that an elemental Ca:P ratio of 1:l may be maintained in most age groups except in infancy where the ratio suggested is 1 :1.5.