Calcium is one of the minerals that you need to be healthy. It helps keep bones and teeth strong, supports the functioning of the heart and blood vessels, and plays a role in the transmission of nerve impulses. Calcium is the most abundant mineral in the body. Ninety-nine percent of the body’s calcium is stored in bones and teeth. One percent goes into supporting the health of muscles, and blood vessels.
The body can get calcium in two ways. One is by consuming food that contains the mineral. The second is by drawing calcium from bone tissue. The body uses bone tissue as a reservoir to draw from to maintain a steady mineral concentrations in the blood. When blood levels of calcium drop, the body “borrows” calcium from the bones to be returned when supplies increase. When bone breakdown exceeds formation, bone loss occurs which increases the risk of osteoporosis.
How much calcium do you need?
The National Academy of Sciences recommends 1000 mg of calcium per day for adults between 19 and 50 years old, and that those age 50 or over get 1,200 milligrams per day. This recommendation may be higher than what most people need. According the Harvard School of Public Health:
these recommendations are based on very short-term studies, and are likely to be higher than what people really need. Currently, there’s no good evidence that consuming more than one serving of milk per day in addition to a reasonable diet (which typically provides about 300 milligrams of calcium per day from nondairy sources) will reduce fracture risk.
Dairy products are a rich source of calcium, but where does someone who doesn’t eat dairy products get calcium? Many people are lactose intolerant, have a casein allergy, or otherwise choose not to consume dairy. Finding whole food non-dairy sources of calcium can be a challenge.
For comparison, below is a chart of different foods high in calcium that are either derived from milk, fortified, or the result of processing:
Dairy and Processed Food Sources of Calcium
|Food||Serving Size||Calcium (mg)
|Yogurt, plain, low fat||8 oz||452|
|Almond milk (fortified)||1 cup||450|
|Cereals ready-to-eat, General Mills, Golden Grahams||3/4 cup||350|
|Milk, non-fat||1 cup||306|
|Cheese, cheddar||1 oz||204|
|Molasses, blackstrap||1 tbsp||172|
|Tofu, made with calcium sulfate||1/4 block||163|
Meeting the daily recommendation for calcium is not difficult if you’re someone who eats dairy or includes fortified foods in your diet. Eating a single bowl of cereal in the morning gets you pretty close.
If you’re a person who doesn’t eat dairy and wants to avoid processed foods, there are several other rich sources of calcium readily available. I’ve listed some of the most common ones in the next table:
Whole Food Sources of Calcium
|Food||Serving Size||Calcium (mg)
|Sardines, canned, with bones||3 oz||325|
|Collards, cooked, boiled, drained, without salt||1 cup||266|
|Spinach, cooked, boiled, drained, without salt||1 cup||245|
|Black-eyed peas, boiled||1 cup||211|
|Salmon, canned||3 oz||181|
|Iceberg lettuce||1 head||97|
|Kale, cooked, boiled, drained, without salt||1 cup||94|
|Green peas, boiled||1 cup||94|
|Almonds||1 oz (24 nuts)||70|
|Broccoli, cooked, boiled, drained, without salt||1 cup||62|
|Sweet potato, cooked, baked in skin, without salt||1 potato||55|
I’m writing this post because I generally avoid eating dairy and since cutting back on processed food I started wondering where I should be getting calcium from. I’ve mentioned before that I’ve included sardines into my diet, but I’ve been buying the boneless ones since those are the only ones I’ve seen at Costco, but now I’ll look for the kind with bones.
I’ve also heard before that broccoli and kale are good sources of calcium, but judging from the chart collard greens and spinach are the green leafy vegetables come out on top in the calcium department. Black-eyes peas are something I’ve never eaten at home, but I plan on picking some up the next time I’m at the grocery store. A more complete listing of the calcium content in food can be found here.
Nutrition can be a murky subject. The optimal amount or the best source of calcium is not clear. Bone health and the amount of calcium absorbed from the food (not just the amount we take in) depend on many factors including activity level, sun exposure, hormones, and the interaction of calcium with other vitamins and minerals in our food sources. I believe variety is important, and also suspect that in the long run choosing whole food sources of calories and nutrients is better than processed or fortified foods.
What do you do to make sure you’re getting enough calcium in your diet?