Make no bones about it: We need calcium. As the most abundant mineral in the body, calcium provides strength and structure for bones and teeth, helps facilitate muscle and nerve function, regulates blood pressure, and mediates hormone secretions. Calcium deficiency (a.k.a. hypocalcemia) can result in symptoms such as tingling in the hands and feet, muscle aches and spasms, brittle nails, coarse hair, confusion, an irregular heartbeat, and, in severe cases, even seizures and heart failure.
Consuming calcium through food is critical for maintaining good health throughout life. Dairy items are typically the first foods people think of when it comes to getting enough of this crucial mineral—but what do you do if you can’t (or choose not to) consume dairy? Good news: There are other ways to hit those coveted calcium recommendations!
How Much Calcium Do You Really Need?
The Food and Nutrition Board (FNB) determines the Dietary Reference Intakes for nutrients across the lifespan. In the case of calcium, the Recommended Dietary Allowance (RDA) for adults is based on the amount of calcium needed to promote bone maintenance and calcium balance.
Around 98 percent of our calcium is stored in our bones, and our body can use that calcium as a reservoir to draw from when calcium drops low in other areas of the body, like in the blood. When dietary calcium intake is lacking, excess calcium may be diverted from the bones, potentially leading to lower bone density and increased risk of fractures. To avoid this, adults should consume 1,000 milligrams of calcium daily. (This goal bumps up to 1,200 milligrams for women over 50 and men over 70).
The Dietary Guidelines for Americans recommends three servings of dairy products daily to help meet calcium needs. It’s easy to see why they make this suggestion when you look at the calcium content of dairy products. One cup of milk contains 300 milligrams of calcium, a cup of yogurt or kefir packs between 200 and 400 milligrams, and an ounce of cheese offers around 200 milligrams. Three servings of dairy foods per day and you’ll put a serious dent in—if not completely knock out—your calcium needs. However, not everyone can eat dairy.
What If You Can’t (Or Choose Not To) Eat Dairy?
If consuming dairy products makes you feel less than your best, you are not alone. According to a Lancet journal review, approximately two-thirds of the world’s population has some level of lactose malabsorption (or intolerance).
Read More: 9 Nutrients You May Be Short On If You Don’t Eat Dairy
In addition to those who cannot digest dairy well, some people have dietary lifestyles that don’t include dairy, such as vegans. In this case, it’s imperative to include ample non-dairy calcium sources in your daily diet to ensure adequate intake.
Good non-dairy sources of calcium include:
- Tofu, 1 cup (when prepared with calcium sulfate): 400-600mg calcium
- Soymilk, 1 cup: 300mg calcium
- Almond milk, 1 cup: 450mg calcium
- Other plant-based milks, 1 cup (when fortified with calcium): 200-500mg calcium
- Calcium-fortified orange juice, 1 cup: 350mg calcium
- Canned salmon, 3oz (with the bones): 200mg calcium
- Canned sardines, 3oz (with the bones): 300mg calcium
- Tahini (ground sesame seeds), 2 Tbsp: 130mg calcium
- Chia seeds, 1 Tbsp: 70mg calcium
- White beans, 1 cup: 160mg calcium
- Kale, 1 cup raw: 50mg calcium
- Collard greens, 1 cup cooked: 270mg calcium
- Spinach, 1 cup cooked: 245mg calcium
- Broccoli, 1 cup raw: 40mg calcium
- Almonds, 1oz: 75mg calcium
- Amaranth, 1 cup cooked: 115mg calcium
- Fortified grains/cereals: amount of calcium varies per product
How does that all ladder up to an adequate daily intake of calcium? To meet your needs, a day of eating might include a breakfast smoothie that contains one cup of almond milk and one tablespoon of chia seeds, a lunch that includes a cup of white beans and a cup of kale, a dinner that incorporates one cup of cooked spinach, and a snack of a serving of almonds before bed.
Optimizing Plant-Based Calcium Absorption
Another factor to consider when meeting daily calcium needs is how well the calcium you eat is absorbed. Dairy products and fortified foods are estimated to have about a 30 percent absorption rate for calcium. Meanwhile, plant-based sources of calcium have a much lower rate of absorption. Spinach, for example, comes in at just five percent.
The reason for the difference in calcium bioavailability among different foods? Look no further than the oxalate and phytate content of those foods. Plants contain oxalic acid and phytic acid, natural compounds that can bind with calcium in the digestion tract, reducing our body’s ability to absorb and utilize it. While almost all plants contain oxalates and phytates, the amounts vary considerably from plant to plant. Foods particularly high in the compounds include spinach, Swiss chard, rhubarb, soybeans, almonds, whole grains, and legumes. So, if the majority of your calcium intake comes from plant foods, it’s best to include more low-oxalate options such as kale and broccoli. Some studies (like this one and this other one) also show soaking and cooking can reduce oxalate content, so if you love spinach, consider eating it cooked instead of raw to maximize that calcium absorption by reducing oxalates.
When Do You Need To Supplement with Calcium?
Despite best efforts to get adequate calcium through their diet, some people who avoid dairy products may struggle to meet their needs consistently. If you’re falling short of the daily recommended 1,000 to 1,200 milligrams of calcium, you might consider filling the gap with a calcium supplement.
For example, if you typically get around 600 milligrams of calcium through your diet (the best way to estimate here is to track your food intake for a few weeks or work with a dietitian), you would add 400 to 600 milligrams of a daily calcium supplement to fill in the remainder. (Something like The Vitamin Shoppe brand Calcium Citrate would be a good option.) Calcium is absorbed best in doses of 300 to 600 milligrams at a time, so it’s best to divide up your dose if taking more than that.
Another important thing to note is that calcium absorption is also affected by other nutrients, including magnesium, vitamin D, and vitamin K. If you’re unsure whether you’re meeting nutrient needs on those fronts, consider supplementing with a calcium-magnesium combo and pair it with a vitamin D/vitamin K supplement to make sure you’re getting the most out of your supplement efforts.
In A Nutshell
No matter how you choose to do it, meeting daily calcium needs is crucial for maintaining healthy bones, muscles, and vascular and nerve health. Aim for 1,000 to 1,200 milligrams daily from food plus supplements, if needed. If you don’t eat dairy products, try to consume a variety of plant-based foods that contain calcium, including leafy greens, soy products, legumes, nuts, seeds, whole grains, and fortified foods. Soaking and cooking your plant foods could help increase calcium absorption. Canned fish (with the bones) is another excellent calcium source. If needed, add a calcium supplement (along with magnesium and vitamins D and K for better absorption and utilization).
Rebekah Feemster, R.D.N., L.D.N., is a registered dietitian nutritionist with a passion for food and fitness. She also holds a Certificate in Adult Weight Management from the Commission on Dietetic Registration. Rebekah has experience working in hospitals, corporate wellness, fitness and rehab facilities, and holistic health. Rebekah finds joy in sharing her nutrition knowledge and helping others develop a healthy relationship with food and their bodies. When she’s not talking about (or making) food, you’ll find her outside doing yoga, hiking, or tending her backyard chickens.