Getting Calcium on a Plant-Based Diet: Everything You Need to Know
By Lisa Simon, RD, and Isabelle Sadler
Calcium is a nutrient that many people fear is lacking in a plant-based diet, as dairy is often peddled as the best source. However, there are many good plant-based sources of calcium; as long as a selection of these is included daily, calcium needs can easily be met on a plant-based diet.
Calcium is an essential mineral
Calcium is the most abundant mineral in the body and plays an essential role in building strong bones and teeth. It is also involved in regulating cell metabolism, enabling muscles to relax, and plays a role in blood clotting after injury. The recommended intake for the general adult population is 700mg daily. However, there are certain medical conditions for which intakes of 1000mg are required. This includes people with inflammatory bowel disease, coeliac disease, or malabsorption conditions, and people with osteoporosis receiving treatment. These needs can still easily be met by consuming a balanced and varied plant-based diet.
The key recommendation from the Academy of Nutrition and Dietetics is to ensure you eat 2-3 daily servings of calcium rich foods with good bioavailability daily. Below we explore these sources and how to include them in your diet.
Green vegetables are a healthful source of calcium
Calcium is abundant in low oxalate, green, leafy vegetables. These include kale, broccoli, bok choy, watercress and rocket. Rocket is a great source of calcium, with 216 mg of calcium per 100 g, making it a great go-to base for salads or to have on the side of a main meal.
Other greens such as spinach, beet greens, and Swiss chard are high in oxalates, which inhibit calcium absorption. Although spinach and kale have similar calcium content (119 mg vs. 130 mg per 100g), your body absorbs more calcium from kale.
Nuts, seeds and legumes are calcium-rich
Other useful sources include tahini, chia seeds, poppy seeds, sesame seeds, legumes, oranges, almonds and almond butter, blackstrap molasses, and dark chocolate. There are many ways to incorporate seeds into your diet. For example, add a tablespoon of chia seeds to your porridge or smoothies, and sprinkle sesame seeds on dishes such as stir fries or salads.
As almonds contain phytates, the body will absorb around 20% of the calcium. However, if they are soaked overnight (in water at room temperature) before eating, the absorption increases.
Drink plant-based milk and eat tofu
In order to meet daily calcium needs, it is helpful to aim for a minimum of 400 mls of fortified plant milk daily. This provides on average 480mg of calcium. Many plant-based milks are now fortified with calcium, but still double check the one you’re using is fortified. A fortified plant-based yoghurt will provide a further 120mg of calcium, and an 80g portion of calcium-set tofu, approximately 320mg. This will provide a total of 920mg of calcium, showing how straightforward it is to meet calcium requirements, even for those with higher needs.
A useful tip for a calcium-rich snack is swapping 2 tbsp of peanut butter for almond butter, as this increases calcium by 73 mg.
While we recommend following a whole foods plant-based diet, there are some other calcium-fortified plant-based foods that can help you meet your needs on days where other whole foods sources are lacking. For example, some plant-based cheeses are fortified with calcium, such as vegan Babybel® which provide 136mg per portion. Calcium-fortified orange juice can also help you to meet your calcium requirements.
Avoid alcohol and smoking
It is important to avoid high intakes of salt, caffeine and alcohol, and avoid smoking, as these are known as ‘calcium thieves’, meaning that they reduce the absorption of calcium from food.
Your body needs vitamin D to absorb calcium
It is also crucial to ensure adequate intakes of vitamin D, as this helps our bodies to absorb calcium. During the summer months, the sun’s rays enable our bodies to make vitamin D, but during the winter months, and for some groups all year round, a daily vitamin D supplement is recommended.
Include exercise in your diet
Finally, aim to include strength training in your weekly exercise regime. This can include bodyweight exercises such as squats and press-ups, running, aerobics classes, or playing tennis. Resistance and impact exercises help maintain bone density as you age, while strong leg and core muscles reduce the risk of falls.
You can find more information from these factsheets on Vitamin D and bone health. For meeting calcium requirements for children, check out our kids’ section.
The data for the calcium content of different foods is taken from Food & Nutrition: National Bioscience Research Infrastructure.