Calcium intake may not be related to fracture risk, in men!

http://jn.nutrition.org/cgi/content/abstract/127/9/1782?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&fulltext=high+protein+bone+health&searchid=1&FIRSTINDEX=70&sortspec=relevance&resourcetype=HWCIT

In conclusion, these results do not support a relation between calcium intake and the incidence of forearm or hip fractures in men.

B-12 may be important for elderly women's bone health:

http://jn.nutrition.org/cgi/content/abstract/133/3/801?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&fulltext=high+protein+bone+health&searchid=1&FIRSTINDEX=90&sortspec=relevance&resourcetype=HWCIT

These results suggest that vitamin B-12 status is associated with bone health in elderly women

Apparently the preagricultural calcium:magnesium ratio was 1:1:

http://www.paleodiet.com/losspts.txt

Studies of our ancestors' pre-agricultural diets indicate that magnesium was probably consumed at about a  1:1 ratio with calcium (8 ).

Wow!! Where did they get all that magnesium?   ETA: Or did they a low amount in both? That seems more likely to me!!

More from the same site:

If you are concerned about bone mineralization, the above factors which
interfere with calcium absorption suggest the following strategies:

1.  get your fibre from fruits and vegetables, minimizing bran consumption;
2.  minimize your salt intake;
3.  spend regular time in the sun, or supplement with vitamin D;
4.  get plenty of anti-gravity exercise;
5.  ensure that your magnesium intake is adequate;
6.  reduce or eliminate dairy products and eggs from your diet;
7.  reduce your sugar intake;
8.  avoid soft drinks;
9.  avoid coffee;
10. do not smoke;
11. get tested for celiac disease.

I don't understand the reasoning to reduce eggs?

I'm not giving up eggs or coffee.

I think he misread the original study. Here's an article referring to it:

http://www.freetrainers.com/FT/jsp/Message.jsp?f_ix=3&t_ix=4210

She notes that the animal and human studies that correlated calcium loss with high protein diets used isolated, fractionated amino acids from milk or eggs.4 Her studies show that when protein is given as meat, subjects do not show any increase in calcium excreted, or any significant change in serum calcium, even over a long period.5 Other investigators found that a high protein intake increased calcium absorption when dietary calcium was adequate or high, but not when calcium intake was a low 500 mg per day.6

That makes more sense. So there's nothing wrong with eggs as long as they aren't processed into isolated, fractionated amino acids.

I've been taking Calcium citrate/magnesium/Vitamin D by CitraCal to help prevent oxalate kidney stones from forming. 500mg twice a day with meals (your body can only absorb up to 600mg at a time). Citrate prevents oxalates from being excreted in the urine (if I remember correctly), and since most of the foods on the Paleo diet (excluding meat) are pretty high in oxalic acid, this is great for calcium supplementation. It is also the best form of calcium to take for absorption, can be taken on an empty stomach, and for people to are prone to constipation. Citrate changes the urine pH to alkaline. Calcium carbonate is the cheapest and most readily available form of calcium via supplements, but it has a poor absorption, has to be taken with a meal and is better for people who tend to have loose stools.

Also, too much Vitamin C is bad for calcium absorption, I think. It increases calcium loss in the urine, in the same way that too much sodium does.