Calcium Supplements: Who Needs Them and How to Take Them

Calcium is important for healthy bones, but that doesn't mean everyone needs a supplement. Many Indian adults can get enough calcium from everyday foods such as milk, curd, paneer and other calcium-rich options. However, if you eat very little dairy, follow a vegan diet or have gone through menopause, you may need to pay closer attention to your calcium intake. A supplement may help if your diet isn't providing enough or your doctor recommends one. And if you are thinking of taking calcium tablets, there's more to consider than the brand. The type of calcium, the dose and when you take it all matter. So, how much calcium do you actually need, and can you get enough from food? Here's how to find out when a supplement makes sense and how to take it safely.

How much calcium does an Indian adult need?

The ICMR-NIN 2020 recommendations set the daily calcium requirement for adult men and women at 1,000 mg. That is a big jump from the 600 mg suggested in 2010, as the ICMR-NIN brief note on the 2020 RDA shows in its comparison tables. This 1,000 mg is your total from all sources. Food counts first. A supplement only fills the gap between what you eat and what you need.

Can you get enough calcium from Indian food?

Many people can, because Indian kitchens already hold good calcium sources. You do not need imported foods or special powders.

• Milk, curd, buttermilk and paneer are the easiest daily sources for most families.

• Ragi (finger millet) is a good plant source. Ragi dosa, ragi mudde or a ragi porridge in the morning adds up quickly.

• Til (sesame seeds), as til chutney, til laddoo or a spoon over salads and vegetables.

• Rajgira (amaranth) seeds and leaves, common in fasting food in many homes.

• Green leafy vegetables such as amaranth leaves, drumstick leaves and methi.

• Small fish eaten with bones, like sardines, if you eat non-vegetarian food.

Getting more calcium into your diet doesn't have to be complicated. A glass of milk at breakfast, curd with lunch, some leafy greens at dinner and foods like ragi or rajgira during the week can all help you get closer to your daily requirement. Think about what you ate yesterday. Did you have milk, curd or paneer? What about ragi, sesame seeds (til) or leafy greens? If your only source of dairy was a little milk in your morning chai, you may not be getting enough calcium.

Also read: Everyday habits that help build strong bones after 50 , for simple ways to include more bone-friendly foods in your family meals.

Who may actually need calcium supplements?

The NIH Office of Dietary Supplements names groups who are more likely than others to have trouble getting enough calcium:

• Women past menopause, because the body absorbs and retains less calcium after menopause.

• People who do not drink milk or eat other dairy products, including people with lactose intolerance, people with milk allergies and vegans.

If one of these fits you, or your doctor has advised a supplement after looking at your diet and reports, it is worth discussing a tablet with them. Your body needs vitamin D to absorb calcium, as MedlinePlus notes. If your vitamin D may be low, ask your doctor to check it. Our article on vitamin D deficiency symptoms and treatment explains how to check this.

Calcium carbonate vs calcium citrate: which one should you take?

Walk into any Indian pharmacy and you will mostly see calcium carbonate, often combined with vitamin D3. Calcium citrate costs more, as MedlinePlus notes. Both work. The right one depends on your stomach, your medicines and your budget.

Calcium carbonate

Calcium carbonate is about 40% elemental calcium by weight, according to a clinical review in Endocrinology and Metabolism Clinics. Elemental calcium is the actual calcium your body can use. So a 1,250 mg calcium carbonate tablet gives you roughly 500 mg of calcium. Because carbonate holds more calcium by weight, its tablets can be smaller for the same dose. Carbonate needs stomach acid to dissolve. MedlinePlus advises taking it with meals. Take it after breakfast or dinner, not on an empty stomach.

Calcium citrate

Calcium citrate is about 21% elemental calcium, as the same review notes. You need more tablets, or bigger ones, to get the same dose. In return, it is absorbed well with or without food. MedlinePlus notes that people with low stomach acid, which is more common after 50, absorb citrate better than carbonate.

A simple way to choose

Calcium carbonate is often a good starting option if you're under 50, eat regular meals and don't take medicines that reduce stomach acid.

Calcium citrate may be a better choice if you:

• Take acidity medicines such as pantoprazole or omeprazole regularly.

• Experience gas, bloating or constipation with calcium carbonate.

• Are older or often skip meals.

• Find it difficult to remember taking supplements with food.

One important thing to check on the label is elemental calcium. This tells you how much actual calcium you're getting from each tablet. For example, a tablet labelled calcium carbonate 1,250 mg typically provides 500 mg of elemental calcium. The numbers look different, but they can describe the same amount of calcium. So, when comparing supplements, look at the elemental calcium amount rather than just the larger number printed on the packaging.

How to take calcium supplements so they work

Your body absorbs calcium better when you take it in smaller amounts. According to MedlinePlus, it's best to take no more than 500 mg at a time. Spreading your doses throughout the day may also help reduce side effects such as gas, bloating and constipation. For example, if your doctor recommends 1,000 mg of calcium from supplements, you could take 500 mg with breakfast and another 500 mg with dinner. If your diet already provides most of the calcium you need, one smaller dose may be enough. If you are new to calcium supplements, your doctor may also suggest starting with 500 mg daily and gradually increasing the dose if needed. Remember to count the calcium you're getting from food too, so you don't end up taking more than you need.

Keep it away from iron tablets and thyroid medicine

Calcium can change how your body absorbs some medicines. MedlinePlus lists iron pills and certain antibiotics among them. This matters if you have been prescribed iron and calcium together. Take them at different times of the day, for example, iron in the morning and calcium after dinner. Thyroid medicine is the other big one. In a 2000 JAMA study, 20 people on long-term levothyroxine took calcium carbonate with their thyroid tablet for three months. Their T4 levels fell, their TSH rose and 20% of them had TSH above the normal range. Levels returned to normal after the calcium stopped. If you take thyroid medicine on an empty stomach in the morning, keep your calcium for lunch or dinner. Ask your doctor or pharmacist about the exact gap.

Side effects and the kidney stone question

Common complaints include constipation, gas and bloating. Spreading the dose across the day cuts down on them. MedlinePlus suggests drinking more fluids, eating more fibre and switching to another form if diet changes do not help. If constipation already troubles you, start with a lower dose or ask about citrate. Kidney stones are a real but smaller risk. The Women's Health Initiative trial gave 36,282 postmenopausal women either 1,000 mg of calcium carbonate with 400 IU of vitamin D3 daily or a placebo for about seven years. Kidney stones were 17% more common in the calcium group. The same trial found a small rise in hip bone density but no significant drop in hip fractures overall. If you have had a kidney stone before, talk to your doctor before starting any calcium tablet. The trial tested tablets, not food, so it's worth starting with your plate.

Do calcium supplements affect the heart?

Researchers still disagree on this, so here are both sides. In 2010, a meta-analysis in the BMJ pooled trials of calcium supplements given without vitamin D. In the five trials with individual patient data, 143 people taking calcium had a heart attack compared with 111 on placebo. That worked out to about a 31% higher relative risk. The authors called for a rethink of calcium supplements for bone health.

In 2016, the National Osteoporosis Foundation and the American Society for Preventive Cardiology reviewed the wider evidence. Their clinical guideline concluded, with moderate-quality evidence, that calcium with or without vitamin D from food or supplements has no clear link, good or bad, with heart disease, stroke or death in generally healthy adults. They said intake within the upper limit of 2,000 to 2,500 mg a day should be considered safe from a heart point of view.

The concern was raised about tablets, not about calcium from food. The practical answer is the same either way: get as much as you can from meals, take a supplement only to fill a real gap and do not take more than you need. If you have heart disease or several heart risk factors, discuss it with your doctor before starting.

Can you take too much calcium?

It is possible to take too much. More is not better with calcium. The upper limit for adults is 2,000 to 2,500 mg a day from food and supplements combined, as the 2016 guideline notes. A calcium tablet, a multivitamin with calcium, a fortified health drink and a dairy-rich diet can add up quickly. MedlinePlus also notes that too much calcium can reduce the absorption of iron, zinc, magnesium and phosphorus. If you take several supplements, our guide on how to audit your supplement routine can help you spot overlaps. Remember too that calcium is only one part of bone health. Strength training, walking, protein and vitamin D all play a part. Our article on whether you can increase bone density covers the full picture.

When to see a doctor

MedlinePlus advises that you do not take more than the recommended amount of calcium without your doctor's approval. It also says to always tell your doctor and pharmacist if you take extra calcium, because it can change how some medicines are absorbed. If you have had a kidney stone, have heart disease or take thyroid medicine, talk to your doctor before you start, for the reasons above. The NIH Office of Dietary Supplements lists what high levels of calcium in the blood and urine can cause: poor muscle tone, poor kidney function, low phosphate levels, constipation, nausea, weight loss, extreme tiredness, frequent need to urinate, abnormal heart rhythms and a high risk of death from heart disease. It adds that these high levels are usually caused by a health condition, not by high calcium intake. See a doctor if you are worried or a symptom is not getting better.

The next time someone at home says you must take a calcium tablet after 40, start with a simple check of your own plate. A glass of milk, a bowl of curd and a ragi dosa on a Sunday may already be doing most of the work.

Sources

• Brief Note on Nutrient Requirements for Indians: RDA 2020 (ICMR-NIN, 2020)

• Calcium supplements (MedlinePlus Medical Encyclopedia, NIH)

• Conventional Treatment of Hypoparathyroidism (Endocrinology and Metabolism Clinics of North America, 2018)

• Effect of calcium carbonate on the absorption of levothyroxine (JAMA, 2000)

• Calcium plus vitamin D supplementation and the risk of fractures (New England Journal of Medicine, 2006)

• Effect of calcium supplements on risk of myocardial infarction and cardiovascular events: meta-analysis (BMJ, 2010)

• Lack of Evidence Linking Calcium With or Without Vitamin D Supplementation to Cardiovascular Disease in Generally Healthy Adults (Annals of Internal Medicine, 2016)

Medical Disclaimer: This article is for general information and is not a substitute for advice from your doctor. Speak to a qualified healthcare professional before starting any supplement, especially if you are pregnant, breastfeeding or taking medication.