The Lowdown on Plant-based Calcium

If you’ve been around for the past 20+ years, chances are you know about the “Got Milk?” campaign. By way of widespread marketing, the association between dairy, calcium, and strong bones is now universal knowledge. Trademark images of “milk mustached” celebrities were plastered on billboards across the country, leading us to believe that the best, and maybe the only, source of calcium comes from dairy products. Simply put, that’s just not true!

Of course, dairy does have a large amount of calcium, and many people get the calcium they need from milk products. But for those of us who do not consume dairy often or at all, there’s good news. You can get plenty of calcium from plant-based sources! As someone who is deficient in calcium, and not the biggest fan of milk (since I was little!), I’ve been on the hunt for plant-based calcium sources that are well absorbed. Here’s what I know…

Why is calcium necessary? And how much do we need? 

Way back on the first night of my first quarter of graduate school, we learned all about calcium–functions, recommended intakes, and food sources. Writing this post has been a good way to refresh my memory. I even pulled out my dusty lecture notes ;)!

Calcium is a mineral used for a number of processes in the body– not just for strong bones and teeth. We need calcium for proper nerve transmission, muscle contraction, hormone secretion, and blood clotting. This is why common signs of calcium deficiency include muscle twitching or cramping, and even irritability or anxiety.

Men need about 1000 mg of calcium per day, while women need a daily intake closer to 1200 mg. Certain populations need to pay close attention to the amount they consume, including:

  • Women going through menopause (also post-menopausal women)
  • Individuals with inflammatory bowel diseases, Celiac’s disease, or compromised gut functions
  • Individuals with certain thyroid conditions
  • Vegans and vegetarians
  • Athletes (especially athletes in any of the above categories)

These populations may not consume enough calcium, or may have inhibited absorption and/or increase excretion of this mineral.

Other factors can decrease the absorption of calcium, even with sufficient intake, such as:

  • excessive intake of sodium and/or phosphorous (especially from soda)
  • caffeine consumption
  • oxalates (more on that later)
  • iron and zinc

The role of calcium in the body also depends on the levels of Vitamins D and K2 and magnesium. Eating calcium-rich foods with foods that have these nutrients is one way to ensure that calcium is available for what it needs to do. Limiting caffeine consumption, decreasing sodium intake if you are eating too much, and eating foods with iron and zinc separate from foods with calcium, are also options for enhancing calcium absorption.

What are some plant-based sources of calcium? 

Plant-based Calcium

Even when we know how much calcium we need (between 1000 and 1200 mg/day), it is difficult to translate that into how many calcium-rich foods we need to eat each day. If you are dairy-free, a good rule of thumb is to include several of the following foods in your daily diet. Check with your doctor or registered dietitian about supplements if you think you may need more calcium.

Plant-based sources of calcium include:

  • Dark, leafy greens:
    • Swiss chard (1/2 cup=184 mg)
    • Collard greens (1/2 cup=152 mg)
    • Turnip greens (1/2 cup=100 mg)
    • Kale (1/2 cup=50 mg)
    • Bok choy (1/2 cup=37 mg)
    • Mustard greens (1/2 cup=32 mg)
    • Spinach (1/2 cup=15 mg)
  • Artichokes (1/2 cup =51 mg)
  • Broccoli (1/2 cup=88 mg)
  • Almonds (1/4 cup=60 mg)
  • Blackstrap molasses (1 tbsp=200 mg!)
  • Edamame (organic if possible; 1/2 cup=50 mg)
  • Sesame seeds (1 tbsp=88 mg)/tahini (1 tbsp=64 mg)
  • Sardines (1 can=351 mg!)
  • Figs (1/2 cup=34 mg)
  • Pumpkin seeds (1/2 cup=30 mg)
  • Chia seeds (1 tbsp=80 mg)
  • Dried herbs
  • Himalayan sea salt (small amount)

Other foods, such as cereals and orange juice, are often fortified with calcium. While these may be alright to consume on occasion, eating an abundance of the above foods is the best way to get naturally occurring calcium.

Some foods, especially spinach, chard, almonds, and soy products, have oxalates, which can bind to calcium and reduce absorption in the body. However, if you cook most of your greens and eat a variety of plant-based, calcium-rich foods, oxalates should not have a serious impact on your absorption. Keep in mind that tea and chocolate also have oxalates, so if you consume these in large quantities and are concerned about calcium, consider limiting them (bummer!).

If you eat a mostly plant-based diet, and want to increase your calcium intake, be sure to bookmark this page for an easy reference!

Cheers to healthy bones!