I'm new to all of this with a recent diagnosis of Osteopenia and Osteoporosis. I'm trying to gather as much information as possible to make an educated decision about what route to take in order to deal with this. I'm so confused about Calcium--what kind to take, how much to take, when to take it, whether or not it actually does any good. Everything I have read talks about the absorption. It seems like no matter how much you take hardly any of it gets absorbed. Can anyone offer some help?



Its really very simple. Your body needs about 300-400 mg/day to be absorbed from ALL the food and/or supplements you swallow each day to maintain a balance between intake and what you excrete in urine, sweat, or use to make new bone. The catch is that a healthy adult intestinal tract and adequate level of vitamin D in the blood, will only absorb about ont third of what is swallowed. Only 20% in post-menopausal women, as estrogen assists the intestinal tract efficiency. So to get 300 mg in, you need to swallow about 1000mg, or 1500 if a post-menopausal woman.
The better calciums are absorbed a little more efficiently, but that only means you need to take less supplement. However, calcium in food is better absorbed than any supplement. So the more you can get from a healthy diet, the less, IF ANY, you need to spend on supplements.
Calcium is an element, and it is the same whether you get it from milk, carbonate, citrate, algea, ground up bones, whatever. The body doesn't care how much you spent to buy it. And taking extra only makes it go out your kidneys faster, and makes your urine more expensive.
ALso, don't get too hung up on "absorption" as they are only measuring how fast it appears in your urine after you swallow it, not how much is incorporated into bone.
Some people will not abosrb certain forms of calcium products, or none of them well at all if they have had bariatric surgery, or have celiac disease, etc, but if this doesn't describe you, then buy the cheapest supplement from a respected name, that doesn't cause constipation or excessive gas (signs that it isn't being absorbed) and use the savings to buy a spa treatment or join a health club or a nice vacation.