A reader asks: My calcium levels were above normal range on a recent blood test and a heart scan revealed minor coronary artery disease, with calcium build-up in the blood vessels supplying my heart.
I take combined calcium and vitamin D supplements for osteopenia so I am a bit concerned. Is there a connection between calcium tablets, calcium in food and calcium in the heart?
Dr Rosemary Leonard says: Calcium is important to maintain strong bones, and also for healthy muscle and nerve function. In the past, people found to have low bone density were often automatically given calcium supplements, in the belief that this would help maintain their bones.
However, there is a limit to the amount of calcium that can be incorporated into bones and an excessively high intake of calcium merely increases the risk of other health problems, such as kidney stones.
Research has also suggested that taking calcium supplements can increase the risk of coronary artery disease and it is thought this is because taking a calcium tablet can rapidly increase levels in the blood, which may lead to calcium being deposited in the the walls of vessels such as the coronary arteries.
Calcium in food leads to a much slower increase in blood calcium levels and no association has been found between a high dietary intake of calcium and heart disease. So ideally calcium supplements should be avoided unless you are unable to get enough calcium from food, especially if your calcium levels are slightly high, even if you have low bone density.
All adults should aim to have at least 700mg a day, from calcium-rich foods such as dairy produce (milk, cheese, yogurt), fish where you eat the bones (such as sardines) and green leafy vegetables. You should continue to take a vitamin D supplement, as this is essential for absorbing the calcium from food into your bloodstream.
There’s more information about the calcium content of different foods at the Royal Osteoporosis Society.
If you have a health question for Dr Leonard, email her in confidence at [email protected]. She regrets she cannot enter into personal correspondence or reply to everyone