Calcium needs during pregnancy and breastfeeding
Calcium supplements
How much calcium is in what foods?
Calcium is the most abundant mineral in the human body and is an important part of our nutritional needs. About 99% of the body's calcium is stored in our bones and teeth. It is here that calcium combines with the mineral 'phosphorus' to make our bones and teeth dense and hard. The remaining 1% of calcium circulates in our body fluids and is necessary for muscle contraction, blood clotting, nerve impulse conduction and the regulation of many hormones. Calcium also activates a protein called 'calmodulin' in the body, which relays messages to specific body cells to help maintain normal blood pressure.
Our bones constantly absorb and release calcium. They act like a 'calcium bank' for our body. During childhood and adolescence our bones absorb more calcium than they release (for storage). As adults the calcium levels remain relatively stable, while in old age we tend to lose more calcium from our bones than we absorb. However, the way our bones absorb, store and release calcium is also reliant on how much calcium we eat in our diets. If our diet is low in calcium, our bones will need to release more calcium into the blood stream, to keep calcium levels in our body normal, for healthy functioning.
While a person can stay healthy for years, even with consistently low calcium in their diet, in later life they can become prone to weakened bones (a condition called 'osteoporosis'). There is also some evidence indicating that adequate calcium in the diet may help prevent high blood pressure, blood cholesterol, diabetes and bowel cancer.
