Did you know that the Recommended Dietary Allowance (RDA) varies by country? For example, in America, the RDA for adults is 1200mg of elemental calcium per day while it is only 800mg per day in Europe and several Asian countries. If, as we claimed Canada’s Food Guide, this contribution is made according to the most rigorous science, then how is it that varies from one country to another? Scientific data, however, cross the borders! The most curious in all this is that osteoporosis is more common where the RDA for calcium is lower … Moreover, researchers have shown in young women, a higher intake to 800mg of calcium daily did not provide any additional benefit on bone development.
Several authors argue that in America, the RDA for calcium was increased due to significant political pressure lobbies milk (such as the Dairy Farmers of Canada). Thus, it is now, for all practical purposes, impossible to achieve the recommended intake without consuming milk and its derivatives.
A maximum absorption
The concept of maximum absorption, yet very important, is too often overlooked when it comes to calcium. The maximum absorption is the maximum that can be absorbed by the intestine. When the intake is too high, the intestine can not absorb the surplus beyond this limit. This concept is well accepted when it comes to vitamin C, magnesium or glucosamine. Indeed, Health Canada issued a dose limit for vitamin C 2000mg per day. This limit is based on the maximum absorption is 1000mg per dose (2 doses per day = 2000mg). In fact, if you take more than 1000mg of vitamin C per dose, you run the risk of having loose stools. When the dose exceeds the absorptive capacity of the intestine, the amount of vitamin C remains unabsorbed in the intestine and can cause loose stools. However, establishing a dose limit by Health Canada seems to imply that to exceed this dose of 2000mg per day is dangerous, what is wrong. (more…)
