Calcium – why do we need it and where should we be getting it from?
Calcium is one of the minerals necessary for strong bones and teeth. It is also important for a healthy nervous system and enables blood to clot properly, muscles to contract and the heart to beat.
Roughly 99% of the calcium in our bodies is stored in the bones and teeth.
Calcium is lost daily through sweat, urine and faeces and since the body cannot produce calcium, it needs to be obtained from the food we eat. If we don’t get the calcium we need, our bodies will take what is needed from our bones, causing them to become weak and brittle.
As we age, calcium deficiency can result in bone loss, low bone density and even broken bones.
Many factors contribute to calcium loss. Calcium can be lost as a natural consequence of aging and people with low levels of vitamin D tend to lose more calcium too. A lack of integrity in the lining of the intestines can also contribute to malabsorption.
Consumption of large amounts of sodium, protein and caffeine play an integral role in calcium loss.
Before you rush out and buy a calcium supplement or drink gallons of milk, it’s important to remember that the body needs other very important vitamins and minerals for the absorption of calcium.
Vitamins D and K, as well as magnesium, help to ensure that calcium is absorbed into the bones. It is not always necessary, or even advisable, for everyone to be taking a calcium supplement.
Where should we get our calcium from?
Food is the best source of calcium. When eating a balanced diet, most people will meet their calcium requirements through their diet. Milk, yoghurt and cheese contain the highest amount of calcium, but sardines with bones and green leafy vegetables are also good sources. Many milk alternatives, cereals and snacks are fortified with calcium.
In order to meet our daily requirements it is always important to consider the bioavailabilty of any nutrient.
Bioavailability is what is actually available for the body to use after consumption. Although plant foods can be a good source of calcium, they can also contain inhibitory substances such as oxalates and phytates which bind to the calcium in the plant and may decrease the absorption. Even though dairy products have high levels of calcium per serving, the bioavailability reduces the actual calcium to about a third of the total calcium value.
Studies show that when fed a relatively low calcium diet, our intestines become more efficient at absorbing calcium and our kidneys conserve it better. When too much calcium is provided, the body adjusts as well by blocking calcium absorption in the intestines and eliminating more via the kidneys. If not eliminated, the excess calcium gets deposited into the soft tissues i.e heart, kidneys, muscles and skin, which makes us vulnerable to illness and even death.
If it is necessary to supplement with calcium, it is best to take 500mg or less, once a day with meals. Taking calcium with meals allows for better absorption due to the action of stomach acid in the process.
It is perfectly safe to supplement with Vitamin D, Vitamin K and magnesium, without calcium, as they ensure that calcium from the diet is absorbed into the bones to keep them healthy.
Listen to my interview with Brad Kirsten from Radio Cape Pulpit on 13 August to learn more.
Listen to my next interview on Thursday at 7.45am