3 Side Effects Of Calcium Supplements You Should Know

There’s no denying that calcium is one of the most important minerals your body needs to keep your teeth and bones healthy. That said, it’s vital to know how much calcium to eat and in what forms. According to the National Institutes of Health, the average daily recommended intake of calcium for an adult is 1000–1200 mg. Those who don’t get an adequate supply of calcium through their diet are often prescribed calcium supplements to avoid calcium deficiency. However, there have been concerns about their safety. Let’s take a look at the types of calcium supplements and the potential health problems they may cause when taken in excess.

Types Of Calcium Supplements

Though calcium is present in many multivitamin and multimineral supplements, its percentage in them tends to vary. So, it’s better to consume supplements that contain only calcium, which are usually of two types:1:


Carbonate: Calcium carbonate supplements are inexpensive and provide 200-400 mg of calcium per pill. These are best absorbed when taken with food.

Citrate: This is a more expensive type of calcium supplement. It is mostly recommended for people over the age of 50 because it is more easily absorbed even on an empty stomach thanks to its mildly acidic nature.


The best results are observed when the entire dosage is split into smaller doses instead of taking it all at once. Calcium absorption is highest when supplements are taken in doses of less than 500 mg at once.

However, excess consumption of these supplements could result in the following side effects.


3 Health Risks Associated With Calcium Supplements

1. Possible Calcium Deficiency

Excess calcium supplement consumption affects blood pH, which causes calcium deficiency and hence osteoporosis in the long run

As strange as it may seem, calcium supplements, which are meant to increase your calcium levels, may actually make you deficient in the nutrient.


Calcium is alkaline in nature and helps maintain the pH of the blood. However, an increased intake of calcium citrate supplements, acidic foods, and acidic sources of calcium like refined and processed foods can have the opposite effect and cause your blood pH to drop. In turn, the calcium that is already stored in your bones starts getting released, leading to a calcium deficiency and osteoporosis in the long run.2

So, if you’re consuming excess calcium citrate supplements, switch to natural alkaline calcium sources like leafy greens and other vegetables along with a limited intake of dairy. You also need to have at least 20 ng/ml of vitamin D in your system in order to promote healthy calcium absorption.3


2. Increased Risk Of Kidney Stones

Consuming calcium supplements regularly may increase the risk of kidney stones

While calcium supplements are usually quite effective in improving calcium levels in your body, daily consumption may increase the risk of kidney stones.4 This makes sense as kidney stones are usually formed as a result of calcium build-up. So, ensure that your calcium supplementation does not exceed 1200–1500 mg a day. Always consult your doctor before you reduce or increase your intake.


3. Heightened Heart Attack Risk

Eating calcium supplements in excess of the recommended dose causes arterial blocks, increasing heart attack risk

After years of debate over the link between high calcium intake and heart disease, researchers have concluded that calcium supplements increase the risk of plaque buildup in arteries.5 This has to do with the psychological construct that taking more calcium pills improves calcium levels. So, most people who take these supplements end up taking more than the recommended dosage every day. This extra calcium begins to stick to the arterial walls, eventually causing a blockage and increasing the chances of a heart attack. On the other hand, a diet rich in natural sources of calcium tends to have a protective effect.


There is a difference in the way your body reacts to calcium in food and calcium taken through supplements. It is likely that the supplements are a more concentrated form of the mineral, making it difficult for your body to process it all at once. Consuming a calcium-rich diet, on the other hand, allows your body to absorb calcium in smaller amounts, reducing the chances of health issues caused by excess calcium intake. Adhering to the recommended dosage of calcium supplements and relying more on natural sources of calcium are the safest ways to ensure adequate calcium intake and stay healthy.