It seems well established that when one is taking in proper amounts of the nutrients involved with improving calcium metabolism (e.g. Vitamin D, K2, Magnesium, etc.) calcium need is reduced.
Assuming an adult is receiving appropriate intakes of such nutrients, what would be a recommended range of calcium intake to shoot for?
Edit: This question has stagnated for a while so I'm throwing on a bounty. Questions about calcium intake in the past like this one and this one have answers suggesting things like "forget about the RDA (of calcium)" and "the Paleo recommendation for calcium is too low", which seem to contradict each other (maybe) and don't give numbers regarding how much calcium we should get on a good paleo diet. I'm hoping for a range (e.g. 1000-1200mg), but feel free to speculate.
The issue is not just how much is recommended, but what food it is in, how your body absorbs it, and the balance of other vitamins and hormones.
The RDA is about 1000mg per day for adults, slightly more for pregnant and lactating women. The World Health Organization suggests that calcium intake lower than 500mg is associated with osteoporosis in countries with high osteoporosis rates. Ramiel Nagel suggests 750 to 1500 mg in his protocol for tooth and gum health (http://www.curetoothdecay.com/Gum_Disease/gum-disease-calcium.htm ). Paul Jaminet suggests eating a healthy diet and a multivitamin, and it should be fine. (http://perfecthealthdiet.com/?p=415 ). Mark Sisson suggests the issue is more about Magnesium, Vitamin D, and Vitamin K2
So, shoot for around 750-1000mg, probably don't go too far over that mark, but don't worry about being under it. Try to get good sources of Magnesium, get some Sun, and eat pastured animals.
Your answer follows directly from your first paragraph, which presumably came from the same sources I follow (WAPF, Masterjohn, etc...).
As such, no calcium supplement should be needed, so long as you are getting calcium in your diet. When I say "getting", I mean not even having to bother to track it because, well, you eat, right? A basic Paleo or WAPF diet with the right meats, veggies, dairy and nuts in whatever moderation moderates you, etc... right?
If you eat even basically from the categories above, you don't need to supplement calcium. Its not a scarce mineral.
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