Calcium is an essential macromineral whose roles in the body are relatively well-known. It strengthens bones and teeth, improves the body's alkalinity, helps our heart muscles to contract and relax properly and more.
Like all minerals, calcium doesn't work alone, but in tandem with other nutrients such as magnesium and vitamin D. For this reason, obtaining our calcium from whole foods - foods whose nutrient profiles have been optimized by nature for superior absorption -- is the best way to remain healthy.
Good natural sources of calcium
Seaweed - It is common to find seaweed in any "best of" list, and for good reason: since seaweed grows in the ocean and is thus unaffected by soil erosion (the process that has significantly reduced the nutritional value of most land-based vegetables), its nutritiousness has remained intact for centuries. And, as it happens, seaweed has always been rich in calcium.
Perhaps the best seaweeds in this regard are kelp, kombu and wakame. One hundred grams of each contain between 150 and 170 grams of calcium, as well as countless other essential nutrients, including iodine. Avoiding seaweed sourced from the Pacific Ocean is a good idea due to possible radiation contamination.
Chia seeds - Though chia seeds are best-known for their high protein and fiber content, they contain similarly impressive levels of calcium. In fact, 1 ounce of these versatile South American seeds provides us with 179 milligrams of calcium, which is 17 percent of our recommended daily allowance (RDA). Of course, it's easy to consume far more than 1 ounce of chia seeds per day, making them one of the easiest foods to consume for correcting a calcium deficiency.
Blackstrap molasses - Blackstrap molasses is the dark, treacle-like byproduct of the sugar cane refinement process. Since it is derived from the sugar cane plant, whose tall roots grow deep into the soil, it contains a large number of nutrients that are seldom found in such quantities elsewhere, including calcium. Specifically, 1 tablespoon of blackstrap supplies us with 123 milligrams of the mineral, or 12 percent of our RDA. Blackstrap is also a good source of magnesium, manganese, selenium, potassium and iron, and makes a great sweetener in baking.
Sesame seeds - These nutty and delicate seeds, which belong to one of the oldest oilseed crops grown on Earth, supply our bodies with 88 milligrams of calcium per tablespoon. Like chia seeds, sesame seeds are incredibly versatile and can be sprinkled on salads and cooked meals, or simply eaten as a snack.
Raw milk - According to the Weston A. Price Foundation, 8 ounces of raw milk - unprocessed milk straight from the cow -- supplies our bodies with 300 milligrams of calcium. Additionally, it contains certain minerals, such as phosphorus and magnesium, which aid the calcium's absorption rate. Unfortunately, milk subjected to homogenization and/or pasteurization does not fare as well. These unnatural processes damage the nutritional structure of the milk, and inhibit the absorption rate of its nutrients.
Incidentally, this fact also applies to other dairy products. Yogurt, cheese and kefir are all excellent sources of calcium when made from raw milk. When made using processed milk, however, their nutrient profile is compromised.
Certain leafy greens - Due to soil erosion, most green vegetables - once considered among the finest sources of calcium -- are now shadows of their former selves nutrition-wise. Fortunately, a number of hardy greens do retain some of their nutritional power. Kale is probably the best example of these (1 cup of chopped kale contains 101 milligrams of calcium), with broccoli and spinach in second and third place respectably.