Calcium is the most abundant mineral in our bodies. Of course you’ve heard before that calcium is important for healthy bones, and in fact 99% of the body’s calcium supply is stored in our bones and teeth where it supports their structure and function. But the other 1% is incredibly important as well! Calcium is necessary for muscle function (including our beating hearts!), proper blood flow throughout our bodies (vascular contraction and vasodilation), intracellular signaling and hormone secretion, and nerve transmission. It’s important stuff!
How much we need:
How much calcium you need in your diet really depends on who you are. We adult people tend to need about 1000mg per day, with an increase to 1200mg/day for women over 50.
Some groups of people need to pay extra attention to their calcium intake as they either don’t get enough calcium in their regular diets, or don’t absorb it well. This includes:
-vegans and vegetarians
-those with compromised gut function such as Celiac or Chrohn’s disease or IBS
-women over 50
Calcium and bone health:
The body very carefully regulates the amount of calcium present in our bloodstream, referred to as serum calcium, so it doesn’t fluctuate with dietary intake. Rather, the body uses bone tissue as a calcium reserve in order to maintain constant concentrations of calcium in our blood, muscle, and intracellular fluids. Our bones are in an ongoing state of remodelling, with constant resorption of calcium into the bloodstream, and deposition of calcium from the bloodstream into new bone.
When we’re young and growing, bone formation exceeds resorption. In the stages of early and middle adulthood, the processes are more or less equal, but in aging adults, especially among postmenopausal women, bone breakdown exceeds formation.
Where to find calcium in your diet:
The first thing that most people jump to when they think about dietary calcium is dairy. While it’s true that dairy is a good source of calcium, it’s not the only one out there! Vegans and lactose intolerants can breathe easy knowing there are lots of plant-based ways to get calcium into your diet.
- Leafy greens such as spinach, kale, bok choy, and collard greens
- Tofu and tempeh
- Beans such as navy beans, chickpeas, and pinto beans
- Sesame seeds or tahini
- Blackstrap molasses
- Dried figs
- Chia seeds
So a recipe like this Tempeh Reuben Bowl with leafy greens, tempeh, and tahini sauce, would be loaded with plant-based protein!
There are also many foods that are fortified with calcium, such as orange juice, non-dairy milks, and cereals, all of which can contribute to your daily calcium intake.
Eating your calcium-rich foods together with vitamin D and magnesium-rich foods will help your body to absorb the calcium more easily. On the contrary, iron and zinc both compete with calcium, so supplements or foods especially rich in these minerals should be avoided at the same time as calcium. Leafy greens are also rich in oxalic acid, which binds with calcium and reduces absorption in the body. Cooking the greens will minimize the oxalate content, however.
Should I supplement?
In general, it should be quite easy to get adequate calcium through your diet. If you’re in one of the at-risk groups mentioned above, however, you should speak to your health care professional about your calcium intake and whether supplementation is right for you.
Calcium supplements can be quite hard on the digestive system, causing constipation and bloating. Taking calcium supplements together with magnesium can help with this, as can taking it with food. It’s also worth noting that the body has a limited capacity to absorb calcium, so rather than taking 1000mg once a day it would be better to take 500mg twice a day.
If you know that you’re prone to kidney stones, it’s especially important to speak to your doctor before you begin supplementing with calcium, as excess or high doses of calcium can cause larger and more frequent stones.
The bottom line
You should be able to get all the calcium you need to meet your daily requirements from a plant-based diet. Include foods such as leafy greens (cooked to reduce the oxalic acid content), beans, and tahini in your diet to boost the calcium content naturally. If you’re concerned about deficiency or are in an at-risk group, speak to your heath care professional about supplementation.