For years and years we’ve been told that calcium is necessary for bone health. While this is true, calcium’s primary role in the body is not bone health. Numerous critical functions are performed by the < 0.5% of calcium that is not in the bones and is found in the blood and inside cells. In fact, these additional functions are so important that, if the level of calcium in your blood drops below a certain level, your body will pull the calcium out of your bones to bring the blood levels up to a minimum level!
The additional functions of calcium include blood clotting, muscle contractions (including your heart), permeability of cells, transmission of nerve signals, and creation of messengers like prostaglandins and leukotrienes.
Interestingly, ~10 years ago, you could buy a straight calcium supplement if you or your doctor thought that your dietary intake was insufficient for your needs. Now, it’s difficult to find a supplement that is only calcium. (** HERE’S THE IMPORTANT PART… **) This is because we have begun to understand how calcium interacts with other nutrients from absorption through utilization. These interacting nutrients include, but are not limited to:
- Vitamin D: sufficient levels are necessary for calcium to be absorbed in the intestine
- Vitamin K: K2 is needed in sufficient quantities for calcium to go into the bone rather than into soft tissues, while K1 is needed for blood clotting
- Phosphorus: during bone mineralization, it is thought that phosphorus is laid down first and then calcium is bound to the phosphorus (for information, magnesium also attaches to phosphorus as part of the bone mineralization process)
- Vitamin C: a necessary component of collagen, which keeps the skin from sagging, but also is part of the structure of bones between which calcium is deposited
- Potassium: exerts a strong influence on blood calcium levels
- Magnesium: also influences blood calcium levels; if you are chronically low in magnesium, you will eventually be low in calcium and potassium also
So, if you are taking a calcium supplement or eating certain foods for bone health (ladies, I’m looking at you!), be sure you are getting enough of the other nutrients so that the calcium is used to keep your bones healthy. Of course, this can be accomplished by a balanced diet. And if you are taking a calcium supplement, you can get one that includes almost all of the above nutrients and is made specifically for bone health.
As an additional note, you don’t have to have dairy to get enough calcium. Lots of other foods have calcium also: clams, oysters, turnip and mustard greens, broccoli, cauliflower, kale, tofu, legumes, nuts, and fortified foods like juices and bread.