In general, calcium absorption begins to decrease as the amount taken increases. The ideal amount to take at one time is up to 500mg of calcium. How much you need depends upon your diet. Calcium is relatively easy to get from the diet; however, many Americans still fail to do so. Generally, calcium supplements should contain 200iu of vitamin D and 250mg of magnesium for each 500mg dose of calcium to ensure optimal calcium metabolism and utilization.
In addition to calcium citrate, calcium carbonate is also common. It is 42% calcium by weight, whereas calcium citrate is 21%. The carbonate form is best absorbed when taken with a meal and the citrate form is unaffected by timing. The dotFIT Super Calcium + uses the higher calcium content of carbonate and has the appropriate vitamin D and Mg as well. Below are calcium intake recommendations. (http://ods.od.nih.gov/factsheets/calcium ).
Recommended Dietary Allowances (RDAs) for Calcium
Age Male Female Pregnant Lactating
0–6 months* 200 mg 200 mg
7–12 months* 260 mg 260 mg
1–3 years 700 mg 700 mg
4–8 years 1,000 mg 1,000 mg
9–13 years 1,300 mg 1,300 mg
14–18 years 1,300 mg 1,300 mg 1,300 mg 1,300 mg
19–50 years 1,000 mg 1,000 mg 1,000 mg 1,000 mg
51–70 years 1,000 mg 1,200 mg
71+ years 1,200 mg 1,200 mg
* Adequate Intake (AI)