Calcium is the most abundant mineral in the body ...primarily found in the bones and teeth. In bone formation, calcium forms crystals that provide strength to maturing bone.
Calcium is needed for more than just healthy bones. It is also important for muscle contraction, blood vessel contraction and expansion, the secretion of hormones and enzymes, and sending messages through the nervous system. A meta-analysis of 56 clinical trials demonstrated a significant impact on heart health as a result of increased calcium intake by 1,000 to 2,000 mg/day.11 In addition, scientific evidence suggests that increased intake of calcium may help to maintain optimal weight as well.12-15
Calcium is an essential mineral that is often inadequately supplied, inefficiently absorbed, or excreted faster than it is being assimilated.70 The citrate salt of calcium has been documented to be well absorbed and utilized by the body.7-10 This is the form many doctors and nutritionists recommend. Calcium citrate dissolves easily even if one doesn’t have much stomach acid. Many people naturally produce less acid as they age, so calcium citrate is a good choice for older adults. The addition of vitamin D3 is also critically important because it stimulates calcium absorption and promotes healthy bone density.71 However, as people age, they often lose the ability to make vitamin D3.72
Calcium and other minerals are best not taken with fiber, because fiber can interfere with their absorption.1,4,5 There is evidence that calcium from supplements and dairy foods may inhibit iron absorption, although it has been very difficult to distinguish between the effects of calcium on iron absorption versus other inhibitory factors, such as phytate.27-29 Although current understanding of this suggests that the inhibition of calcium on absorption of iron is of short duration and the body has adaptive mechanisms.30
Calcium supplements are best taken with meals. They should always be taken with a full glass of water, juice, or other liquid to enhance solubility.31 If calcium-containing formulas are taken only once daily, they may be best taken in the evening.32