Calcium from Seeds: Sesame, Chia and Poppy Compared, and What to Expect

Calcium is best known for building and maintaining strong bones and teeth, but it also helps muscles and nerves work. Most adults need around 1,000 milligrams a day, with somewhat more for older women and for teenagers. Dairy foods are the classic source, but seeds can contribute, especially for people who eat little or no dairy.

Which seeds contain calcium?

Sesame seeds are the standout. A tablespoon of unhulled sesame seeds gives about 80 to 90 milligrams of calcium, while hulled seeds have much less, since the shell holds most of the calcium. Tahini made from unhulled seeds is a good source, though many tahini products use hulled seeds, so check the label. Poppy seeds contain about 125 milligrams per tablespoon. Chia seeds provide roughly 140 to 180 milligrams in two tablespoons. Flax, sunflower and pumpkin seeds contain smaller amounts.

Absorption matters

What counts is how much your body takes in, not just how much is in the food. Seeds contain oxalates and phytic acid, which bind calcium and reduce absorption. Sesame is high in oxalates, so the calcium is absorbed less well than from dairy. This does not make seeds useless. It means they are a helpful contributor, not a replacement for a balanced calcium-rich diet.

Better together

A varied approach works best. Other plant sources include fortified plant milks and tofu set with calcium, canned fish with soft bones if you eat fish, kale, bok choy, broccoli and almonds. Spinach is often cited but contains oxalates that lock up most of its calcium. Vitamin D helps you absorb calcium, which comes from sunlight, fortified foods and supplements where advised, and weight-bearing exercise helps maintain bone health.

Simple ways to eat more calcium-rich seeds

Spread tahini on toast or stir it into oatmeal. Sprinkle toasted sesame over vegetable stir-fries. Make chia pudding with fortified plant milk. Add poppy seeds to muffins or noodle dishes. Grinding sesame seeds helps release their calcium, since the seeds are tiny and often swallowed whole.

What about supplements?

If you think you are not getting enough calcium, speak to a doctor or dietitian before taking tablets. Very high doses can cause constipation and, in some people, kidney stones, and calcium can interfere with some medicines.

Who should check first?

People with kidney disease or a history of kidney stones should ask their doctor about sesame and other high-oxalate seeds. If you take thyroid medicine, certain antibiotics or osteoporosis medicines, calcium can affect absorption, so ask your pharmacist about timing. Sesame is a major allergen, and anyone with a seed allergy should avoid it. Pregnant and breastfeeding women have higher calcium needs and should discuss them with their healthcare provider.

This article is general information, not medical advice.