Calcium

True calcium deficiencies are uncommon in the Western world, regardless of what the dairy industry tells us. The bigger problem is that many athletes are unable to use the calcium they already have in their bodies. Poor calcium metabolism, rather than a deficiency, is almost at epidemic proportions. The end result is that not enough calcium gets into the muscles, bones, and other tissues, with the remaining excess calcium potentially depositing in the joints, tendons, ligaments, or even the kidneys as stones. (Plaque that clogs the arteries can also contain this calcium.)

In order for your body to properly metabolize calcium, and more effectively absorb it from food, you must have sufficient vitamin D. This nutrient is free and plentiful, yet many are surprised to find that some athletes don’t have enough. (The important issue of vitamin D and the sun is discussed in chapter 32. Just remember that without sufficient vitamin D, calcium cannot be properly absorbed and regulated, and that most problems of insufficient calcium are really due to low levels of vitamin D.)

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Another important issue regarding calcium is to consume enough calcium-rich foods; this is easily done without supplementation through good dietary practices. And it does not necessarily mean eating a lot of dairy foods. (Recall that dairy fats are highest in B fat and can contribute to inflammation.)

Consider the moderate amounts of calcium in the following single servings of non-dairy foods:

 

 

 
  • Salmon: 225 mg
  • Sardines: 115 mg
  • Almonds: 100 mg
  • Seaweed: 140 mg
  • Rainbow trout: 100 mg
  • Spinach: 135 mg
  • Green beans: 100 mg
  • Collards: 125 mg

Two other important issues regarding calcium are absorption from the intestine (which is significantly influenced by vitamin D) and, after absorption, getting the calcium into the bones and muscles. Absorption is the first step to using calcium in the body.

In general, smaller amounts of calcium are better absorbed than larger amounts, whether from food or supplements. If a small amount of calcium is present in the intestine, 70 percent may be absorbed, for example, while a larger amount of calcium may have only a 30 percent absorption rate. If you’re taking calcium supplements, it may be best to take a lower dose several times a day rather than a large dose once daily. Even though vegetables contain smaller amounts of calcium, larger percentages are absorbed compared to milk. So in some situations, a serving of broccoli may result in more calcium getting into the body than a serving of milk.

The stomach’s natural hydrochloric acid is also very important in making calcium more absorbable. Neutralizing stomach acid has a negative effect on calcium absorption and a serious impact on digestion and absorption of all nutrients.

Excess phosphorus intake can be very detrimental for calcium use, pulling it out of muscles and bones. Most soft drinks contain large amounts of phosphorus—and the people who drink them risk significant calcium loss from bones, muscles, and other areas of the body.

The type of calcium supplement may be associated with absorbability. For example, calcium carbonate is more poorly absorbed than calcium lactate or calcium citrate. This is due to the alkaline nature of carbonate and the acidic nature of lactate and citrate.

Taking too much calcium in supplement form can disturb the body’s complex chemical makeup. For example, too much calcium can reduce magnesium. Most athletes may be in need of more magnesium than calcium—it’s necessary for most enzymes to work, including the ones important for fat metabolism. And the best sources of magnesium are vegetables.