How to Include More Calcium-Rich Foods in Your Diet

Got milk? Millions of us remember this ad campaign, originally kicked off in 1993 and still ongoing through today, albeit with gaps. The goal of the ad campaign was to promote sales of dairy products, primarily milk, for their health benefits. The most widely promoted of those benefits was the high levels of calcium present in milk.

Calcium is a critical nutrient used throughout our bodies, most notably in the bones. In fact, the bones act as the reservoir of calcium, and the body will add or remove calcium from your skeleton in order to maintain calcium homeostasis elsewhere in your body.

There's no question that calcium is critical, but what is it used for, how much do you need, and how can you make sure you're getting enough?

How Your Body Uses Calcium

By far, the most important use of calcium in the body is in your bones and teeth. Calcium is the building block used to create and maintain healthy bones and teeth, including the development of bones as you grow and age, the maintenance of those bones as you live your life, and the ability to heal those bones if something happens to them.

Another important use of calcium is as fuel for muscles. Calcium is a critical nutrient used when your brain tells your muscles to contract. When you engage a muscle, nerves stimulate the body into releasing calcium, which contracts the muscle fibers; by pulling the calcium back out of the muscles, they relax. This is the basis of how your muscles work in a simple sense. With inadequate calcium, muscle regulation decreases.

Knowing this, you might assume that calcium is a critical part of your heart and cardiovascular system. This is true, but it goes beyond its use in flexing the heart muscle. Calcium is also used in the process of blood clotting, and there's a potential link between calcium and blood pressure, with higher calcium consumption correlating to lower blood pressure.

Calcium is also used as a cofactor for many different enzymes and enzymatic processes throughout the body. While much more study is needed to enumerate every use and reaction, it's possible that adequate calcium consumption is related to a lower risk of high blood pressure in women during pregnancy, improved cholesterol values across the board, and even a lower risk of colorectal adenomas, a non-cancerous tumor.

How Much Calcium Your Body Needs

It's clear that you need adequate calcium to maintain proper bodily function. Your body has a lot of calcium in it – the average adult body contains 1,200 (for women) and 1,400 (for men) grams of calcium. You're constantly using calcium, and the body cannot synthesize calcium out of nothing, so you need to get enough in your diet to maintain your health. How much is enough?

The amount of calcium you need starts at 200 mg per day when you're born and rapidly increases throughout life as you grow. It's also a nutrient where the amount you need increases over time, especially when you're elderly. The older you are, the harder it is for your body to maintain the calcium in your bones, so the more you need to keep it up. The exception is the spike in need during adolescence, when your final growth spurts use more of it to establish you as an adult.

These are the recommended daily intakes for calcium, as determined by the Food and Nutrition Board at the National Academies of Sciences, Engineering, and Medicine.

The Risks of Low Calcium

What happens when you don't get enough calcium in your diet?

The biggest and most common impact is to bone strength. Over time, low levels of calcium intake forces the body to pull more and more calcium from the bones. This leads to osteoporosis, a common disease seen in the elderly. Your bones grow brittle and weak, and are more likely to break, especially on impact or when falling. The stereotype of "falling and breaking a hip" is largely reflective of osteoporosis.

In children, inadequate calcium intake can stunt growth and cause rickets.

With calcium associated with blood pressure, cardiovascular health, and cholesterol, it's also possible that all of these can be affected negatively by low levels of dietary calcium, but there have been relatively few studies looking into these links. After all, we already know of major reasons to maintain adequate calcium; adding more evidence to the list is unlikely to change that need.

For example, an observational study of over 77,700 adults found that higher calcium intakes were associated with a lower risk of colorectal cancers. However, clinical trials examining the use of calcium supplements to reduce the risk of cancers have had mixed results.

In general, there are three groups most at risk of calcium deficiency.

• People reaching old age. The older you are, the more your body may struggle to use the calcium you have and the more you may need to counteract it.
• Postmenopausal women. Menopause causes a decrease in estrogen production, which in turn leads to reduced calcium absorption. It's estimated that as much as a third of postmenopausal women have osteoporosis.
• People who avoid dairy products. By far, the best dietary source of calcium is dairy, so people who are lactose intolerant, allergic to milk, or who avoid dairy for dietary reasons like veganism are all at greater risk of not consuming enough calcium in their diet.

Fortunately, it's not terribly difficult to get calcium through your diet.

Dietary Sources of Calcium

By far, the best dietary sources of calcium are dairy products. Fortified foods, dark green vegetables, and some other vegetables are also good options.

Here are some of the best sources:

While dairy products are the best, you can also get a decent amount of calcium from many other sources. A well-balanced diet is likely to have small amounts of calcium in just about everything you eat, so you may not need to do much to get what you need.

Before we move on to actionable advice, there's one thing we haven't yet discussed: the ingredient that makes calcium work.

Calcium's Enabler: Vitamin D

Unfortunately, it's not as simple as consuming enough calcium in your foods to maintain adequate levels and avoid the problems that come from low calcium. In order for your body to be able to absorb and use calcium, you must also have adequate amounts of its enabler, vitamin D.

Vitamin D, also known as calciferol, is a fat-soluble vitamin. It's found in some foods naturally, it's fortified into other foods, and it's commonly seen as a dietary supplement. It's also synthesized naturally by the body when exposed to UV radiation from the sun, which triggers synthesis in the skin. This produces an inert version of vitamin D that is then processed into usable vitamin D.

Therefore, in order to ensure that the calcium you eat is properly used, you need enough vitamin D. While sunlight exposure is the best way to get enough vitamin D, dietary consumption helps.

The recommended daily intake of vitamin D is:

These numbers were developed based on an assumption that you get little to no sun exposure and don't synthesize meaningful amounts of vitamin D endogenously. It's difficult to give specific sun exposure recommendations due to geographic differences in cloud cover, ozone cover, daylight hours and more. Moreover, UV rays are carcinogenic, making it difficult to recommend, and adequate sunblock also blocks the triggering of vitamin D synthesis.

Dietary sources of vitamin D are limited to fortified foods like milk and cereal, fatty fish such as trout and salmon, eggs, cheese, and mushrooms.

How to Make Sure You're Getting Enough Calcium

What steps can you take to make sure you're getting enough calcium to stay healthy and keep your bones strong?

Eat more dairy products. As you can see from the chart above, yogurt, mozzarella, milk, and cottage cheese are all very good for calcium and are often packed with other healthy nutrients as well. They also frequently are fortified with additional vitamin D to ensure that the calcium is better absorbed.

Fish. In particular, fatty fish such as salmon, tuna, and trout are all good options. They, too, are packed with other healthy nutrients, including omega-3 fatty acids. Fish with soft, edible bones, like sardines, also include more vitamin D from those bones.

Fortified options. Many foods are fortified to include more vitamins and minerals like vitamin D and calcium. However, some of these foods are also full of excess sodium and preservatives, which you may want to avoid. Carefully consider the foods you choose, and aim for a more whole-food, natural diet when possible.

If you're vegan or unable to eat dairy products, focus on calcium-rich non-dairy foods. These foods include tofu made with calcium sulfate, soybeans and soy milk, and dark leafy greens like kale.

In general, a healthy diet shouldn't have a problem getting adequate calcium, but without adequate vitamin D, that calcium may not be put to proper use, so make sure you get enough of both.

Are Calcium Supplements a Viable Option?

Yes and no. If a person’s diet is lacking in Calcium, then a supplement to help reach the recommended daily intake is a reasonable option. However, supplementing with Calcium to exceed the recommended daily intake does not appear to offer any benefits, and may be associated with an increased risk of heart disease.

Instead of relying on supplements, you should strive to maintain a healthy diet and lifestyle and use small-scale supplements to make up for minor gaps in nutrition. That's what I do with MicroVitamin, a mixture of nutrients I've developed to supplement my diet.

Taking a large dose of any nutrient is likely to have side effects. Calcium is no different. People taking calcium supplements often report stomach problems and constipation, and some find an increased risk of developing kidney stones.

Sources

1. UpToDate – Calcium and Vitamin D for Bone Health: The Basics: https://www.uptodate.com/contents/calcium-and-vitamin-d-for-bone-health-the-basics?search=Calcium%20in%20Foods&source=search_result&selectedTitle=2%7E150&usage_type=default&display_rank=2
2. National Institutes of Health Office of Dietary Supplements Calcium Fact Sheet for Health Professionals: https://ods.od.nih.gov/factsheets/Calcium-HealthProfessional/
3. Mayo Clinic – Calcium and calcium supplements: Achieving the right balance: https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/in-depth/calcium-supplements/art-20047097
4. National Institutes of Health Office of Dietary Supplements Vitamin D Fact Sheet for Health Professionals: https://ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/
5. Independent associations of dairy and calcium intakes with colorectal cancers in the Adventist Health Study-2 cohort: https://pubmed.ncbi.nlm.nih.gov/28735581/
6. Calcium plus vitamin D supplementation and health outcomes five years after active intervention ended: the Women's Health Initiative: https://pubmed.ncbi.nlm.nih.gov/24131320/