Calcium is a mineral that is necessary for
healthy bones and for several important functions in the human body. It can be obtained through the diet (such as through dairy products) or through supplementation. Calcium supplements are among the most popular
dietary supplements available. Although many of the benefits of calcium have been known for quite some time, recent research suggests that there may be some interesting, previously unpredicted benefits of the supplement.
Most of the calcium in the human body is stored in the bones and the teeth. While many people think of bones and teeth as being permanent, unchanging structures, they are actually being constantly broken down and rebuilt. It is absolutely essential to keep a certain steady level of calcium in the blood. If blood calcium levels are too low, the body will break down bone and teeth to increase the blood calcium levels. If the blood levels are high, then the body uses the extra calcium to rebuild bone and teeth.
The important functions of calcium in the body are too numerous to list entirely in this article. Quite simply, the body cannot function without adequate amounts of calcium in the blood (which is why the body will weaken the bones if necessary to preserve the calcium levels in the blood in the case of a
calcium deficiency). A few of the ways calcium might work for specific uses include:
- Calcium carbonate works as an antacid by binding to hydrochloric acid in the stomach.
- It can bind to phosphate in the digestive system (preventing the phosphate from being absorbed), and it is sometimes used to help prevent or treat high phosphate levels in people with kidney disease.
- It might work to lower blood pressure by causing the kidneys to excrete more sodium through the urine. Sodium causes water retention, which can contribute to high blood pressure (hypertension).
- It might work for weight loss by inhibiting the formation of fatty tissue and increasing the breakdown of fatty tissue, possibly by decreasing levels of the hormone calcitriol.
- Women often experience a drop in calcium levels just before their menstrual periods. This might explain how the supplement may work for premenstrual syndrome (PMS) symptoms.
The mineral is very effective for some uses. However, many uses have only a little scientific evidence in their favor, and some have almost none at all
(see Does Calcium Work? for more information).
Because it has been studied quite a bit, good information about calcium dosing is available. For some of the less studied uses, the most effective (and safe) doses have not yet been established. Adequate Intakes (AIs) and Tolerable Upper Intake Levels (UL) have been established for the mineral.
Some people think that vitamins or minerals are naturally free of side effects. However, this is simply not the case. This supplement has been reported to cause various side effects, including (but not limited to):
(Click Calcium Side Effects to learn more, including any potentially serious side effects that you should report immediately to your healthcare provider.)
Most people can safely take calcium, especially at reasonable dosages. However, some people may be more likely to experience problems. Therefore, you should talk with your healthcare provider prior to taking the supplement if you have:
- Achlorhydria (low or absent stomach acid)
- An overactive parathyroid gland (hyperparathyroidism)
- High phosphate levels in the blood (hyperphosphatemia)
- Low phosphate levels in the blood (hypophosphatemia)
- Kidney disease, such as kidney failure (renal failure)
- Kidney stones
- Sarcoidosis
- Any allergies, including allergies to foods, dyes, or preservatives.
Also, let your healthcare provider know if you are:
Make sure to tell your healthcare provider about all other medicines you are taking, including prescription and non-prescription medicines, minerals, and herbal supplements.
(Click Safety of Calcium for more information, including any available warnings and precautions.)
What If I Take a Calcium Overdose?
It is possible to take too much of this supplement. Overdose symptoms may vary, depending on factors such as the dosage and whether it was taken all at once (a single massive overdose) or over a long period of time (a chronic overdose).
