Calcium Supplements, Uses, Effects and More.

What is Calcium?

The mineral calcium makes up almost 2% of your total body weight. Your bones and teeth store 99% of the calcium in your body, while the rest can be found in your blood, tissue, and fluids.

Your body needs calcium for muscles to contract and expand, for nerves to carry messages to your brain, and to continue building strong bones. Calcium also moves blood in veins throughout your body and secretes hormones and enzymes that affect almost every bodily function.

What Are The Effects of Calcium and Why Do We Need It?

Calcium is the workhorse of the body’s minerals. Calcium is vital to countless functions in the body, including muscle contraction, blood vessel contraction and expansion, hormone and enzyme secretion, and sending messages through the nervous system. And of course, calcium is also vital to building bones.

But calcium alone isn’t enough to build bone; it takes a small army of vitamins and minerals to help do that.

Indeed, vitamin K2, strontium, and trace minerals have been revealed to play an important role in increasing bone mineral density, even among postmenopausal women. Numerous studies have linked trace mineral deficiencies with lower bone density and weaker bones. Much like vitamin D aids in calcium absorption, trace minerals also work alongside calcium to increase bone density.

Proper calcium levels are vital to bone health, but have also been linked to healthy blood pressure, reduced rates of colorectal cancer, and even weight loss. The benefits of calcium — and there are many — cannot be understated.

Signs and Symptoms of Calcium Deficiency

Another huge benefit of adequate calcium intake is simply avoiding deficiency. That may seem obvious, but when you understand what happens to your body when it doesn’t get enough calcium, you’ll realize how important adequate intake really is.

Among other symptoms, calcium deficiency can lead to lethargy, muscle cramps, brittle fingernails, and loss of appetite. In more severe cases, calcium deficiency can lead to mental confusion and skeletal malformations like curvature of the spine.

Early recognition of these symptoms is immensely important to reversing the negative impact of calcium deficiency. In most cases, catching the problem early and working to boost overall calcium levels can be enough to ward off the progression of more severe symptoms.

Discover more in-depth information on our post: Signs and Symptoms of Calcium Deficiency.

Factors Affecting Calcium Absorption

Vitamin D

Vitamin D helps you dramatically improve calcium absorption. Vitamin D is available in some foods as well as through sun exposure. If adequate vitamin D intake from food and sun exposure can’t be achieved, supplementation is recommended in the form of vitamin D3.

Vitamin K

Vitamin K2 works with vitamin D to help osteocalcin (noncollagenous protein hormone found in bone and dentin) hold on to bone-building minerals like calcium. Learn more about Vitamin K2 and the benefits of this key ingredient to bone health.


Magnesium deficiency alters your calcium metabolism and the hormones that regulate calcium. Check out our magnesium pages for more information on magnesium deficiency and magnesium benefits.


Children’s calcium absorption rate can be as high as 60% because their bodies need calcium to build strong bones. Absorption slowly decreases to 15–20% in adulthood, dropping even lower as you continue to age. Because your calcium absorption declines with age, recommendations for dietary intake of calcium are higher if you are 51 or older.


Pregnancy does not impact daily calcium recommendations. Current calcium recommendations for pregnant and not pregnant women are the same because intestinal calcium absorption increases during pregnancy, meaning the same amount of calcium is better utilized by pregnant women.


Calcium absorption decreases with age, with an additional drop in absorption during menopause. Poor calcium absorption is also affected by certain dietary fibers, alcohol consumption, and smoking, while positive improvements have been linked to certain dietary fats and estrogen therapy.

Recommended Dietary Allowance (RDA) of Calcium

How much calcium is enough? Well, that depends on a couple of things. Age and gender are the two biggest factors when it comes to your recommended daily intake of calcium. How you get that calcium affects how easily it will be absorbed. Your body has less work to do when calcium comes from plant sources because the plants actually predigest the calcium for you, making it easily absorbed and body-friendly.

Below is a chart with recommended amounts for adequate daily calcium intake:

Age Men Women Pregnant Lactating

0-6 months*

200 mg

200 mg

7-12 months*

260 mg

260 mg

1-3 years

700 mg

700 mg

4-8 years

1000 mg

1000 mg

9-13 years

1300 mg

1300 mg

14-18 years

1300 mg

1300 mg

19-50 years

1000 mg

1000 mg

1300 mg

1300 mg

51-70 years

1000 mg

1200 mg

71+ years

1200 mg

1200 mg

*Adequate Intake (AI)

Getting that much calcium from diet alone, while not impossible, can be difficult, which is why so many choose to supplement their daily intake.

Assorted fruits and veggies that are high in calcium

Getting Calcium From Your Diet

Adequate calcium is vital to your overall health and wellbeing. On top of plant-based calcium sources being easily digested, they’re also abundant. Nut milks, soy products, and blackstrap molasses are all very high in calcium. Vegetables like collard greens, bok choy, and even turnip greens also provide solid servings of the bone-building nutrient.

If you’re looking for a more traditional source, look to animal products for hearty doses of calcium, including milk, cheese, and sardines. (To see which milk types contain the most calcium, check out our “How Much Calcium is in Milk?” page).

But even more than being a source of calcium, these foods are part of a balanced diet. Each food has its own combination of vitamins and minerals, which can help your body function at every level. Sardines are a great source of vitamin D, while nuts and beans are chock-full of boron.

To learn more about calcium sources in everyday foods, check out our guide to calcium-rich foods.

Unfortunately, despite its natural abundance, most people still don’t get enough calcium through food alone. Only 15% of girls between the ages of nine and 13, and less than 10% of girls 14–18 are actually getting enough calcium on a daily basis. Those years are critical to creating the bone mass that will sustain them through the rest of their lives. That’s why supplements aren’t just for women going through menopause.

Keeping in mind the importance of other nutrients when it comes to calcium absorption, less than 7% of adults over the age of 51 are able to meet their daily vitamin D requirements through diet alone.

A major reason people aren’t taking in enough calcium from their food — despite the abundance of calcium-rich foods available — is a mineral deficiency in our crops.

Since the early 1960’s, the levels of vitamins and minerals in our produce has diminished dramatically. The same vegetables you ate as a kid now have substantially less nutritional value than they used to.

An alarming whitepaper from the Nutrition Security Institute revealed the unsettling truth. In the US alone, topsoil is eroding 10 times faster than it’s building up. Our soil quality is rapidly deteriorating, and it’s taking the minerals along with it. And that means your bones are being robbed of the building blocks they need to stay strong.

So while eating a diet that includes calcium-rich foods is a good start, it’s not nearly enough to give you the adequate amounts needed for optimal health in most cases.

Should You Be Taking Calcium Supplements?

Simply put, most people aren’t getting enough calcium through diet alone. Widespread calcium deficiencies in girls are setting up a whole generation of calcium-deficient women. And if you don’t get enough calcium through your diet alone, the logical solution is to supplement.

When it comes to finding a calcium supplement, look for one that is packed full of not only calcium but synergistic vitamins and trace minerals.

A plant-based supplement like AlgaeCal Plus not only provides a daily dose of body-friendly predigested calcium, but all the additional nutrients needed to properly absorb and use that calcium. AlgaeCal Plus is specifically formulated to support bone health while not only stopping bone loss but actually building new bone altogether. It also comes with all 13 clinically supported bone-building nutrients, like magnesium, boron, selenium, and more.

So when you go looking for a calcium supplement, look for one that can meet all your needs in one bottle.