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Non-Dairy Sources of Calcium

They say you can’t squeeze blood from a turnip but can you squeeze calcium from kale? Calcium is an important part of a healthy diet. It plays an essential role in bone density, muscle contraction, nerve function, blood pressure stability and healing. Today, a large percentage of people look to dairy as their primary source to meet their daily calcium needs.

But what are the options for those who are seeking non-dairy sources of calcium? Can they meet their daily needs without dairy? Currently, the Recommended Daily Allowance (RDA) for calcium ranges from 800mg to 1200mg per day. If dairy is the standard, one cup of milk, for example, contains 300mg of calcium. Let’s compare this to some whole foods sources of calcium per serving based on USDA research: 

Tofu 350 mg per ½ cup serving

Tapioca 300 mg per ½ cup serving

Chia seeds 300 mg per 1.5 ounces serving

Collard greens 210 mg per ½ cup serving

Kale 205 mg per ½ cup serving

Bok Choy 190 mg per ½ cup serving

Figs 135mg per 5 fig serving

White Beans 120 mg per ½ cup serving

Turnip Greens 104 mg per ½ cup serving

Spinach 99 mg per ½ cup serving

Almonds 93 mg per ¼ cup serving

Sesame Seeds 51 mg per 1 tablespoon serving

This is just a short list of a large number of plant-based whole foods that contain calcium. Perusing the list, it’s easy to see that consuming a predominantly plant-based diet of whole foods would easily meet the RDA guidelines for daily calcium intake.

Consuming more calcium is not the only answer to building a stronger body. A Yale study that analyzed 34 published studies from 16 countries found that the countries with people who consumed the highest levels of dairy and animal-based products had the highest levels of osteoporosis.

Additionally they found that South Africans’ daily calcium intake was 196mg and yet they were nine times less likely to suffer hip fractures than their American counterparts.1 This study highlights the fact that other factors (i.e. high sugar or protein intakes, sedentary lifestyle) and important aspects of calcium metabolism, including absorption and excretion, work in concert to maintain strong bones and a healthy body.

Simply put, consuming more calcium does not directly correlate with stronger bones.  Calcium absorption is a crucial second step. When one cup of milk is consumed, approximately 32% of the calcium is absorbed. Compare this to the calcium absorption from leafy green vegetables, such as bok choy, that produce a 40-70% absorption rate.2 Applying a little math we see that approximately 96 mg of calcium is absorbed from one cup of milk compared to 132mg of calcium from 1 cup of bok choy (70% absorption of 190 mg).

Almonds follow closely behind milk with 21% absorption, beans average 17% and spinach, because of higher oxalate levels, trails the group at 5%. The final aspect of calcium metabolism that has been largely ignored is excretion or losses. Excessive dietary protein and sodium will increase calcium losses in the urine.

Also, medications such as antacids containing aluminum have been shown to increase calcium excretion. Consuming the Standard American Diet while meeting calcium goals may still result in inadequate calcium balance due to losses from excessive protein and sodium intakes. 

This highlights the key concept that bone health is more than just calcium intake. Minerals, Vitamin D and activity are all important components of healthy, strong bones. One of the most important additional benefits of whole food sources of calcium is that they supply minerals and micronutrients that promote bone health. Minerals such as manganese, boron, zinc, copper, strontium and magnesium are found in these whole foods and are critical components of calcium metabolism and bone health. Without these micronutrients, calcium assimilation into bone is limited.

Eating a variety of these non-dairy sources of calcium helps to ensure an adequate supply of these vital minerals. Eating whole foods is a great way to get the calcium and minerals that help promote a healthy body and bones. Consider some of these ways of adding non-dairy foods with calcium to your diet:

•Add legumes and beans to a chili or stew

•Mix tofu as well as kale and other greens into soups

•Top salads with broccoli, seaweed, almonds and sunflower seeds

•Spread almond butter or hummus on whole grain or pita bread

What other ways do you boost your calcium with non-dairy sources?

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1.Abelow B, Holford T, Insogna K. Cross-cultural association between dietary animal protein and hip fracture: A hypothesis Calcified Tissue International 1992, Volume 50, Number 1, 14-18
2.Heaney RP, Weaver CM. Calcium absorption from kale. Am J Clin Nutr 1990; 51:656-657.