Calcium is an important part of every 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 of calcium to meet their daily needs. Are there other and perhaps better options for those who are seeking non-dairy sources of calcium? Is it possible to meet your daily needs without dairy? Let’s explore the answers to these important questions. 

Currently, the RDA for calcium ranges from 800mg to 1200mg per day depending on age and sex. If dairy is the standard for calcium, one cup of milk, for example, contains 300mg of calcium. Now, compare this to some whole food sources of calcium per serving based on USDA research:

•       tofu 350mg
•       tapioca 300mg
•       Chia seeds 300mg (1.5 ounces)
•       collard greens 210mg
•       kale 205mg
•       cooked bok choy 190mg
•       figs 135mg (5 whole)
•       white beans 120mg
•       cooked turnip greens 104mg
•       cooked spinach 99mg
•       almonds 93mg
•       sesame seeds 51mg (1 tablespoon)
•       dried herbs 21mg (1gram)

This is just a short list of a large number of plant-based whole foods that contain calcium. Perusing the list, it is 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 build stronger bones, however. A Yale study analyzed 34 published studies from 16 countries and found that the countries that 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, protein intakes, medications, sedentary lifestyle) and the all-important aspects of calcium metabolism including absorption, assimilation, and excretion, work in concert to maintain strong bones and a healthy body. Consuming more calcium does not directly correlate with stronger bones and may in fact be harmful. 

Once calcium enters your mouth it begins a journey that may or may not lead to your bones. Reaching the stomach, calcium begins to be absorbed into the blood stream aided by stomach acid. But not all of the calcium in food is absorbed. 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 132 mg of calcium from one cup of bok choy. Almonds follow closely behind milk at 21% and beans average a 17% absorption rate. Spinach, because of higher oxalate levels, trails the group at 5%. Vitamin D is also a critical component in calcium absorption and levels should be checked and corrected to normal if necessary.

One of the most important additional benefits of whole food sources of calcium is that they supply minerals and micronutrients that aid in the assimilation of calcium into the bones. 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. 

The final aspect of calcium metabolism that has been largely ignored is the excretion or loss of calcium that occur on a daily basis. Excessive dietary protein and sodium can increase calcium losses in the urine.3 Medications such as antacid medications containing aluminum have also been shown to increase calcium excretion. Consuming the average American diet, and meeting calcium goals, may leave you with an inadequate calcium balance due to losses from excessive protein and sodium intakes.

Whole foods are packed with calcium and a wide variety of minerals that help promote a healthy body and bones. Consider adding some of these non-dairy foods to your diet today and watch your health and bones improve:
•       legumes and other beans to add a healthy dose of calcium to a chili or stew
•       tofu, figs, kale and other greens added to soups or salads
•       broccoli
•       ¼ cup of seaweed
•       1 ounce of almonds or sunflower seeds sprinkled on a salad
•       almond butter
•       sesame seeds
•       salmon
•       carrot juice
•       hummus
•       quinoa

1.     Heaney RP, Weaver CM. Calcium absorption from kale. Am J Clin Nutr 1990; 51:656- 657
2.     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
3.     Sellmeyer DE, Stone KL, Sebastian A, et al. A high ratio of dietary animal to vegetable protein increases the rate of bone loss and the risk of fracture in postmenopausal women. Am J Clin Nutr 2001;73:118-22.