Your Best Sources of Calcium
Don’t be fooled by deceptive labeling. Dairy products are a poor choice.

By Jeff Novick, R.D.

Nutritionists do not compare foods or nutrients in terms of weight, volume, or portion size. Comparing foods that way can be very misleading. For example, let’s compare calcium content in various foods by volume.

One cup calcium
Skim Milk 300 mg.
Kale 180 mg.
Bok Choy 158 mg.
Broccoli 95 mg.

Compared by volume, milk seems to be the winner. However, your body absorbs calcium differently from different foods. For example, only about 32 percent of the calcium in milk is absorbed, while 54 percent of the calcium in bok choy is absorbed.

So let’s modify the chart and compare by rate of absorption:
One cup calcium percent absorbed
Skim Milk 300 mg. 32% 96 mg.
Kale 180 mg. 59% 106 mg.
Bok Choy 158 mg. 54% 85 mg.
Broccoli 95 mg. 53% 50 mg.
Compared by absorption, kale wins and milk doesn’t seem so special.

Now we make our final adjustment. Let’s compare not by volume and rate of absorption,but by equal number of calories and rate of absorption:

100 calories calcium percent absorbed
Skim Milk 334 mg. 32% 107 mg.
Kale 449 mg. 59% 265 mg.
Bok Choy 787 mg. 54% 425 mg.
Broccoli 189 mg. 53% 100 mg.

As you can see, calorie-for-calorie, leafy green vegetables are far better sources of calcium than skim milk, and the same can be shown for other dairy products.