All supplements are not created equal. To expand on this idea, it is my opinion that well-formulated multivitamins meet five major criteria: Optimal Bioavailability: Bioavailability describes how well a nutrient is broken down, absorbed and entered into the body’s bloodstream. Ultimately, a high bioavailability means that there is a greater amount available to be delivered and utilized by the body’s tissues. Every vitamin, mineral and nutrient can be absorbed at different rates depending on its form, whether it’s taken with or without food or other minerals, and on other factors. Higher quality supplements use the most bioavailable forms. **Note: Many
Ensuring that you are taking the best form of calcium for your body will not only benefit your bones, but will also save you from spending money on a type of calcium supplement that is not going to work well for you or which may provide little value to your body. With so many forms of calcium on the market, choosing one can be complicated indeed. Certain types of calcium supplements may be better for some types of people than others. Some of the most common forms of calcium supplements that are available include: calcium carbonate, oyster shell calcium, calcium gluconate, calcium citrate, calcium citrate-malate, calcium hydroxyapatite, calcium lactobionate, and others. But there is more to choosing the right calcium supplement than just choosing the right form of calcium. Be sure to keep the following factors in mind when choosing a calcium supplement that’s right for you.
Determining Elemental Calcium Content
Calcium supplements always come as a salt or a chelate, meaning they are attached to a carrier compound. Elemental calcium refers to the actual amount of calcium in the supplement. The Supplement facts panel on a calcium supplement is useful for determining how much calcium a serving actually contains. Be aware of the serving size when calculating the amount of calcium that is in one serving. Also, paying attention to how it’s displayed is important. Below are some examples to help you understand how much calcium is in your supplement. (These same rules can be applied to other minerals as well.) The examples below use calcium citrate, which is about 20% calcium.
If the label states the amount of elemental calcium per serving or per capsule, then there’s no guessing.
Calcium citrate (providing 200 mg elemental calcium) 1000 mg
If the label states that one capsule or one serving provides 1000 mg of calcium citrate, then you can assume that one capsule or serving only provides 200 mg of calcium.
Calcium citrate 1000 mg
If the label states that one capsule or one serving provides 1000 mg of calcium from calcium citrate (using words or parentheses to indicate the source), then you know that you are getting 1000 mg of calcium in that serving.
Calcium (citrate) 1000 mg
Solubility and Bioavailability
At one time it was believed that the better a substance dissolved in water, the more absorbable it was by the body, and therefore more bioavailable. This is often the case, but not always. Several older studies from 1987 and 1990 measured both the solubility in water as well as absorption in humans of various forms of calcium. They found that low water solubility didn’t always translate into low absorption in the body. The authors thought that this could be due to the added stomach acid. However, there are of course numerous other variables in the human digestive tract including enzymes, bile salts, etc. In addition, a recent study found that calcium forms that yield higher blood levels of calcium (better bioavailability) don’t necessarily have better bone-building effects than those than yield lower blood levels of calcium.
Factors Affecting Calcium Absorption
Even if you’re getting the right type and amount of calcium, there are other factors at work that you should be aware of. If you’re deficient in vitamin D, you’ll only absorb 10% of your calcium instead of the average 30%. In addition, deficiencies in other vitamins, minerals and trace minerals like vitamin K, magnesium, zinc, copper, manganese, strontium and boron among others can contribute to poor bone health. In one study, women who were supplementing with calcium citrate-malate along with trace minerals zinc, copper and manganese experienced positive bone-building effects, while the women taking just calcium or just trace minerals continued to lose bone. Regular weight-bearing exercise also helps your body to better use the minerals and the calcium that you consume to stimulate bone growth.
Taking too much calcium will actually cause you to absorb less of it. It’s the body’s natural way of protecting itself. Take no more than 500 mg calcium at once. Excessive sodium, caffeine and alcohol intake can increase calcium loss, so it’s important to replace the calcium (and other minerals) you might be losing in these cases. People living in areas with high levels of calcium in the drinking water, or people who consume more calcium from their diet, may not need to supplement as much calcium. Oxalate and phytate compounds found in certain vegetables and grains reduce calcium absorption. If you’re trying to get your calcium from vegetables in a non-dairy, non-supplemented diet, you may have to consume a lot more calcium from food than you would from milk or from a supplement.
That’s enough info for one sitting. Stay tuned for part 2 where we will examine the different forms of calcium used in calcium supplements and discover what’s what and what’s best!
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