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Calcium in Tofu: Everything You Need To Know

You are looking for ways to add more calcium to your meals. What about the calcium in tofu?

In this article, you will learn about the different types of tofu, and which is best to eat for calcium. You will also discover some other important nutrients in tofu. If tofu is new to you, you will learn some of the many ways to prepare it.

Let’s go.

How To Make Tofu

Bean curd is another name for tofu. Tofu is made in a similar way to how cheese is made from the curds of milk.

First you soak, crush and boil the soybeans. Then separate the liquid from the  solid portion, or curd. A substance called a coagulant speeds up that separation process.

In the same way, you can add an acid like lemon juice to milk to make it separate, or curdle. The acid is a coagulant.

Calcium or magnesium salts are the most common tofu coagulant. Citric acid or Glucono-Delta-Lactone, another type of acid, are also used. You can also coagulate soy with an enzyme like papain.

After the liquid drains off from the curd, you are left with soft cakes of tofu. Tofu comes in extra soft, silken, firm or very firm varieties.

Manufacturers use Glucono-Delta-Lactone (GDL) to make silken or soft tofu. Firm blocks of tofu are usually made from magnesium chloride (nigari), calcium chloride or calcium sulfate

Nigari is made from seawater. After you remove sodium chloride (table salt) from the water, you are left with nigari, which is mostly magnesium chloride salts.

Which Tofu Has the Most Calcium?

You might have guessed that tofu made with calcium salts has the highest calcium content.

Calcium-set tofu has approximately equal amounts of bioavailable calcium as cow’s milk. It takes 1.2 servings of calcium-set tofu to equal the amount of absorbable calcium in the cow’s milk (1). This amount of tofu is 5.4 ounces (2).

A product set with both calcium and magnesium has a lower calcium content. Many brands will list 10% of the Daily Value on their label, which is about 120 mg calcium.

Be sure to read your label to find out how much calcium is in your tofu.

Here is how the USDA database compares the calcium content of different types of tofu. These values are all for 100 grams of tofu, except the dried frozen tofu. A serving of tofu is usually around 85 grams.

Firm tofu prepared with calcium sulfate683 mg calcium
Dried frozen tofu – 1 piece (17 grams)362 mg calcium
Extra firm nigari tofu (magnesium chloride)282 mg calcium
Firm tofu prepared with calcium sulfate and nigari210 mg calcium
Salted and fermented tofu46 mg calcium
Silken tofu, either firm or soft31 mg calcium

*Silken tofu is often made with Glucono-Delta-Lactone, which does not contain calcium.

Other Nutrients in Tofu

Tofu is an amazing way to supplement your protein intake. Protein is an important nutrient if you want strong bones and muscles. A serving of firm tofu can add at least 9 grams of protein to your meal. 

Silken tofu is not as high in protein. A serving only contributes 3 or 4 grams to your meal.

Tofu also provides other bone-friendly minerals like iron, magnesium, potassium, copper, zinc and selenium. You can also find many of the B vitamins in tofu.

Soy products are an official FDA cholesterol-lowering food. They are correlated with decreases in serum cholesterol, low-density lipoprotein (LDL) and triglycerides (3). 

Soybeans contain phytoestrogens known as isoflavones. These include the compounds genistein and daidzein. Research is showing that soy isoflavones have the potential to decrease bone resorption and enhance bone formation. However, most of the research is done with isolated compounds and supplements, not with actual foods like tofu (4).  So we don’t really know how much tofu you would need to eat to get this benefit.

Most commercial soybean farmers use large amounts of glyphosate. Be sure you are buying tofu made from organic and non-GMO soybeans.

How Do You Eat Tofu?

Tofu is a bland, soft food that is easy to add to many dishes. You can eat it either raw or cooked.

You can press firm or extra firm tofu to remove most of the water. This allows it to hold its shape better.

Pressing is easy. Just fold up a clean dish towel into a square a little bigger than your tofu block. Cover the top of the tofu with several folded paper towels, or another dish towel. Then place a reasonably heavy object on top. The idea is to press the tofu firmly, without squishing it so much it loses it’s shape. A cast iron frying pan works well. Leave it alone for at least 30 minutes.

Here are some ways to add tofu to your meals:

  • Use soft or silken tofu in creamy sauces, scrambled eggs, smoothies, quiche or chocolate mousse.
  • Use silken tofu to make a ranch salad dressing.
  • Add chunks of soft tofu to tacos.
  • Cut firm tofu into small squares and add to a stir fry.
  • Deep fry firm tofu squares.
  • Add firm tofu to soups or stews.
  • Cut firm tofu into squares and bake or pan fry until golden.

Final Thoughts and a Freebie

Tofu can add plenty of calcium, protein and other minerals to your meals. Make sure you check labels, because different types of tofu contain different levels of calcium and protein.

Firm tofu made with calcium chloride or calcium sulfate provides the highest levels of these nutrients.

Are you wondering about other superfoods that can build up your bones? Grab my amazing freebie Seven Superfoods To Strengthen Your Bones. Best of all, it comes with twenty easy recipes to help you add these foods to your meals.

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