This week in nutrition I’m learning about bone health. It’s not only a fascinating topic, but also pretty startling. It seems there are quite a few things about calcium that I didn’t know, and maybe you didn’t either.
Calcium of course can be easily obtained through food, mainly dairy products. The body only absorbs a percentage of any calcium consumed or taken by supplement, and the AI for calcium in adults aged 19-50 is 1,000 mg per day. Adults over age 50 require 1,200 mg per day, and adolescents age 15-18 need 1,300 mg per day. Not all of us consume that much calcium in our diets, and so we require a supplement.
Here’s where calcium can get a little scary. First of all, you can’t take a calcium supplement at the same time as iron, zinc, magnesium or phosphorus. The calcium may interfere, and cause you to not absorb the other minerals, possibly leading to a deficiency in one or more of them if you aren’t getting enough from your diet. Not only do I take magnesium every morning right after taking my calcium, but I also didn’t realize that my calcium supplement contains a small amount of magnesium and zinc! While looking at calcium supplements in the store to replace mine, I found that at least half the calcium on the shelf also contains at least one of these other minerals that it interacts with. It also makes me question what the point of a multivitamin is, when they contain all of those minerals as well. If they are not going to be absorbed, then why am I taking them to begin with?
As if that wasn’t enough, it turns out that calcium supplements that are made with “natural” substances like oyster shell, bone meal or dolomite can contain dangerously high levels of lead. It has been suggested that the safest calcium supplements will have the words lead free, “purified”, and will have the USP (US Pharmacopeia) symbol on the bottle. I found one with the symbol. None that say lead free or purified.
It’s also important to remember that the body can’t absorb more than 500 mg of calcium at a time, so taking high doses of it will not meet your needs. It’s much better to take a few smaller doses throughout the day, with a meal for slower and better absorption. Interestingly enough, the only doses I saw on the shelf were 600 mg and 1,200 mg. I will continue to search for a lower dose, but at this point I’m not convinced I will find it.
If you’re starting to think maybe you shouldn’t bother with a calcium supplement, please consider that we reach peak bone density at age 30, and begin losing density by age 40. That’s a lot of years of losing bone mass. It’s also important to know that if you don’t consume enough calcium, your body will break down bone in order to get it. We need calcium for many important functions of the body, including allowing our muscles to contract and relax.
Still thinking a calcium supplement is too much trouble? The best dietary sources are skim milk, low-fat cheeses and nonfat yogurt. You can also get a large amount from ice cream, regular cheese and whole milk, although you’ll pay for it in saturated fat and high calories. The only dairy product that is not a good source of calcium is cottage cheese, which loses most of the calcium when it is processed. Not a dairy fan? Hit up the leafy, green vegetables like kale, collard greens, turnip greens, broccoli, cauliflower, green cabbage, brussels sprouts and Chinese cabbage. And if all else fails, many packaged foods are calcium fortified, including orange juice, soy milk, rice milk, and even tofu.
I don’t know about you, but I’ll be shopping around until I find a safer supplement, and taking them separately from my other minerals from here on out.
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