Calcium citrate is a form of calcium used in some calcium supplements. It is particularly useful for people with low stomach acid, such as many elderly people or people who take acid-reducing medications, since other forms of calcium need an acidic environment for proper absorption. In addition, unlike other forms of calcium, it is well absorbed, even on an empty stomach (other types of calcium should be taken with food).
Some people think that vitamins or minerals are naturally free of side effects. However, this is simply not the case. Calcium citrate 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 you should report immediately to your healthcare provider.)
Most people can safely take
calcium citrate, especially at reasonable dosages. However, some people may be more likely to experience problems than others. 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, vitamins, and herbal supplements.
(Click Safety of Calcium for more information, including any available warnings and precautions.)
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 always being broken down and rebuilt. It is essential to keep a certain steady level of calcium in the blood. If blood calcium citrate levels are too low, the body will break down bone and teeth to increase these levels. If the blood levels are high, the body uses the extra calcium citrate to rebuild bone and teeth.
Is Calcium Citrate Effective?
Calcium citrate is 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 citrate 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 (ULs) have been established for the mineral.
When determining an appropriate dose for calcium citrate, be sure to remember that every 1000 mg of calcium citrate contains only 211 mg of elemental calcium.
What If I Take a Calcium Citrate Overdose?
It is possible to take too much calcium citrate. 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).
