Calcium from food is not linked to heart attacks, and for most adults it’s the safest way to meet your needs. The worry is about calcium supplements: some analyses found a small rise in heart attack risk, others found none, so the sensible approach is food first and tablets only when you actually need them.
Here’s what the research says, how much calcium you need, where to get it in a normal Indian diet, and who should take a supplement.
How much calcium do you need?
Needs change with age. The figures below are the US recommended intakes summarised by MedlinePlus, along with the upper limits (the most you should get per day from food and supplements combined).
| Group | Daily calcium | Upper limit per day |
|---|---|---|
| Children 4 to 8 years | 1,000 mg | About 2,500 mg |
| Children and teens 9 to 18 years | 1,300 mg | About 3,000 mg |
| Adults 19 to 50 | 1,000 mg | 2,500 mg |
| Men 51 to 70 | 1,000 mg | 2,000 mg |
| Women 51 to 70 | 1,200 mg | 2,000 mg |
| Everyone over 70 | 1,200 mg | 2,000 mg |
| Pregnant or breastfeeding, 19 to 50 | 1,000 mg | 2,500 mg |
Other countries set slightly different targets (the UK, for example, uses 700 mg for adults), so don’t worry if your doctor quotes a different number. The point is to get roughly this much on most days, not to hit an exact figure.
Where calcium comes from in an Indian diet
You don’t need dairy at every meal, but it helps. According to MedlinePlus, a cup (about 240 ml) of milk or fortified soy milk gives about 300 mg, a small bowl of yogurt (about 170 g) about 300 mg, and around 40 g of cheese about 300 mg. So two glasses of milk and a katori of curd already cover most of an adult’s day.
Other useful sources:
- Ragi (finger millet). It’s unusually rich in calcium for a grain, about 344 mg per 100 g, roughly ten times more than wheat, according to a 2021 review in Frontiers in Sustainable Food Systems. Ragi roti, ragi dosa and ragi porridge all count.
- Tofu and fortified soy milk, which suit vegans.
- Small fish eaten with the bones, such as canned sardines.
- Leafy greens such as broccoli and kale. Spinach (palak) is not a good source because the calcium in it is poorly absorbed.
- Almonds and calcium-fortified foods such as some cereals and juices.
If milk upsets your stomach, lactose-free milk, curd and hard cheese are often tolerated better. For signs that you might be running low, see our post on calcium deficiency warning signs.
Do calcium supplements raise heart attack risk?
This is where the debate started. In 2010, a meta-analysis in the BMJ by Bolland and colleagues pooled trials of calcium supplements given without vitamin D. Among 8,151 people with individual data, those on calcium had a higher rate of heart attack (hazard ratio 1.31). There was no significant increase in stroke or death.
A year later, the same group re-analysed data from the Women’s Health Initiative and other trials and concluded that calcium, with or without vitamin D, “modestly” increased cardiovascular events, with about a 24% higher relative risk of heart attack.
Those findings were debated, partly because the original trials were set up to study bones, not hearts. In 2016, the US National Osteoporosis Foundation and the American Society for Preventive Cardiology reviewed the evidence and concluded, with moderate confidence, that calcium with or without vitamin D has no beneficial or harmful link to heart disease, stroke or death in generally healthy adults, as long as total intake stays within the upper limit.
So the honest answer is: if supplements add any risk, it’s small, and the experts don’t fully agree. That’s a reason not to take calcium tablets “just in case”, not a reason to panic if your doctor has prescribed them.
Does calcium in food clog your arteries?
It’s a common worry, because heart scans can show “coronary artery calcification”. But that calcium is part of plaque that builds up from cholesterol, inflammation and damage to the artery wall over years. It isn’t simply milk calcium being deposited in your arteries.
The MESA study, which followed more than 1,500 US adults with clean heart scans for 10 years, found that people with the highest total calcium intake actually had a lower chance of developing artery calcification. People who took calcium supplements, though, had a somewhat higher chance (relative risk 1.22). This is observational data, so it can’t prove cause, but it fits the pattern: food calcium looks fine, while large doses from tablets are less certain.
Vitamin D and calcium work together
Your gut needs vitamin D to absorb calcium well, which is why many supplements combine the two. Sunlight on bare skin is the main natural source, and food adds a little (oily fish, egg yolks, fortified foods). If you’re unsure about your levels, our guide to vitamin D deficiency signs is a good starting point.
More isn’t better. The NHS advises adults not to take more than 100 micrograms (4,000 IU) of vitamin D a day, because long-term excess can push blood calcium too high and damage the kidneys and heart. The high-dose weekly sachets sold in India should only be used on a doctor’s advice.
Who actually needs a calcium supplement?
A supplement makes sense when food can’t reliably cover your needs. That might be you if:
- your doctor is treating osteoporosis or thin bones and has asked you to take calcium alongside your bone medicine
- you don’t eat dairy and don’t regularly have fortified soy, tofu or ragi
- you’re an older adult with a small appetite
- you have a condition or medicine that affects calcium absorption (your doctor will tell you)
If you do take one, a few practical tips from MedlinePlus:
- Your body absorbs calcium best in doses of 500 mg or less at a time. Split larger amounts across the day.
- Calcium carbonate is cheaper and absorbed better with food. Calcium citrate costs more but works with or without food.
- Check the label for the amount of elemental calcium, and count what you already get from food. Most people only need to fill a gap of a few hundred milligrams, not take 1,000 mg on top of their diet.
Calcium and kidney stones
Supplements and food behave differently here too. In the Women’s Health Initiative trial of more than 36,000 postmenopausal women, calcium plus vitamin D supplements raised the risk of kidney stones by about 17%.
Calcium in food is a different story. The US National Institute of Diabetes and Digestive and Kidney Diseases says calcium doesn’t cause calcium stones and, in the right amounts, can bind other substances in the gut that would otherwise form stones. So if you’ve had a stone, don’t cut out milk or curd on your own. Ask your doctor first, and read more on the causes and symptoms of kidney stones.
Medicines that don’t mix well with calcium
Calcium can bind to some medicines in the gut and stop them being absorbed. Timing matters.
| Medicine | What to do |
|---|---|
| Levothyroxine (thyroid tablet) | Take calcium carbonate at least 4 hours before or after your thyroid tablet, as advised by MedlinePlus. See our hypothyroidism guide for how to take it. |
| Iron tablets | Calcium reduces iron absorption. Take them at different times of day. |
| Some antibiotics (ciprofloxacin and similar quinolones, doxycycline and other tetracyclines) | Calcium, including from milk and antacids, can block absorption. Ask your pharmacist for the exact gap for your antibiotic. |
| Antacids | Many antacid tablets are calcium carbonate. Count them in your daily total. |
When to see a doctor
See a doctor before starting calcium or vitamin D supplements if you have kidney disease, have had kidney stones, have a parathyroid problem, or take thyroid, heart or bone medicines. Get medical help soon if you notice:
- severe pain in your side or back that may spread to the groin, blood in your urine, or fever with that pain (possible kidney stone)
- constant thirst, passing a lot of urine, nausea, constipation or confusion while taking high-dose calcium or vitamin D (possible high blood calcium)
- tingling around the mouth, fingers or toes, or muscle cramps and spasms (possible low calcium)
Call 112 straight away for chest pain or pressure lasting more than a few minutes, pain spreading to the arm, jaw or back, sudden breathlessness, or sweating with chest discomfort. If you can’t tell if chest pain is gas or your heart, read how to tell gas pain from a heart attack, but don’t wait at home to find out.
Frequently asked questions
Should I stop my calcium tablet because of heart risk?
Not without talking to your doctor. If it was prescribed for osteoporosis, the bone benefit usually matters more. Ask whether you still need the full dose once your diet is taken into account.
Is milk bad for the heart because of calcium?
No. Studies link calcium from food with no extra heart risk. If you’re watching saturated fat, toned or skimmed milk has the same calcium as full-fat milk.
Can I get enough calcium without dairy?
Yes, with planning. Use ragi regularly, tofu or fortified soy milk, small bony fish if you eat fish, and greens other than spinach.
Is calcium with vitamin D safer than calcium alone?
Not clearly. The 2011 BMJ re-analysis found a similar signal for both, while the 2016 guideline found no harm for either within safe limits. Vitamin D helps absorption, but it doesn’t remove the need to avoid excess.
What does a heart “calcium score” have to do with diet?
Very little directly. A calcium score measures calcified plaque, which reflects long-term artery damage. Lowering cholesterol, blood pressure and blood sugar and not smoking matter far more than cutting calcium from food.
This article is for general information and is not a substitute for advice from a doctor. If you have symptoms or a health condition, please consult a qualified healthcare professional.
