If you’re anything like me, you associate the word calcium with healthy bones and a glass of milk. In truth, calcium is responsible for way more than your bones—and dairy isn’t the only source of calcium there is. We all know calcium is important in keeping our bones and teeth healthy, but that’s not all it does, says Michelle Routhenstein, a registered dietitian, nutritionist, and the owner of Entirely Nourished. Routhenstein notes that calcium is necessary for the proper functioning of our muscles, vascular constriction, and vasodilation—which means that calcium is important in promoting heart health and maintaining a healthy blood pressure. Unfortunately, global estimates suggest that very few people get enough calcium. This calcium deficiency can result in a number of adverse effects on the muscles and bones. So, how do we ensure we’re getting enough calcium? Which calcium-rich foods should we eat? And how can we make sure our bodies are absorbing the calcium effectively? HealthyWay spoke to some experts to find out.
How much calcium do I need?
The amount of calcium you need at any given time will fluctuate, because our bones are constantly breaking down and rebuilding into new bone, says Routhenstein. “The balance between bone breakdown and rebuilding changes with age,” she says. “Bone formation exceeds breakdown in periods of growth in children and adolescents, whereas in early and middle adulthood both are relatively equal.” As adults age, bones break down more than they form. According to the National Institutes of Health, adults ages 19 to 50 need about 1,000 mg of calcium per day. After age 50, women in particular need to increase their calcium intake to around 1,200 mg per day, especially because postmenopausal women are likely to develop osteoporosis. Children ages 9 to 18 need around 1,300 mg daily because their bodies are forming new bones rapidly. Routhenstein points out that your recommended daily allowance (RDA) of calcium will remain the same if you’re pregnant or lactating. Of course, it’s always possible to have too much of a good thing. People ages 19 to 50 shouldn’t exceed 2,500 mg of calcium a day, children ages 9 to 18 should have less than 3,000 mg per day, and those 51+ years of age shouldn’t exceed 2,000 mg of calcium. [pullquote align=”center”]Getting enough calcium is more complicated than simply taking in food with high levels of calcium.[/pullquote] “High calcium levels can cause kidney damage, soft tissue calcification, kidney stones, and constipation,” says Routhenstein. Routhenstein points out that to exceed these levels, one would usually have to take too many calcium supplements—it’s very hard to take in too much calcium from food alone.
What You Need to Know About Calcium Absorption
Before we look at the calcium-rich foods we should all be eating, it’s important to note that getting enough calcium is more complicated than simply taking in food with high levels of calcium. Certain minerals and vitamins can affect the way your body absorbs calcium. For example, vitamin D helps your body absorb calcium, says Routhenstein. “Milk [and] some yogurts and cereals are often fortified with vitamin D. Vitamin D is also found naturally in some foods such as cod liver oil, salmon, egg yolks, sardines, mackerel, and tuna,” she says. “Vitamin D can also be formed in the body when exposed to UV rays.” There are certain factors that can make it harder for your body to absorb the benefits of calcium-rich food. For example, excess salt, caffeine, and alcohol, as well as high levels of oxalic acid and phytic acid, can decrease calcium absorption. Routhenstein explains that this is because those substances bind to calcium, making it harder for the body to absorb it. “High oxalic acid–containing foods include spinach, collard greens, cauliflower, rhubarb, sweet potatoes, and beans,” Routhenstein says. “High phytic acid–containing foods include fiber-containing whole grains, beans, seeds, and nuts.” Of course, this isn’t to say that those foods are categorically bad; it’s just a reminder that moderation is key.
Which foods are the best sources of calcium?
If you want to increase your calcium intake, there are a number of calcium-rich food sources that you can indulge in, and many of them are vegan and vegetarian friendly! According to the experts, the following foods are the best sources of calcium.
Most of us know that dairy is a calcium-rich food. Yogurt is one of the best sources of calcium. Eight ounces of yogurt contains 42 percent of the RDA for calcium. Eight ounces of milk, on the other hand, can supply you with about 30 percent of the RDA. Cheese is also an excellent source of calcium, with parmesan, ricotta, and mozzarella being particularly rich in calcium. Other dairy products that are rich in calcium include buttermilk and ice cream (yum!).
Although this is another dairy product, it deserves its own subcategory. Kefir, which is a tart-tasting, fermented milk drink, is a great source of calcium, vitamin D, protein, and probiotics, according to Routhenstein. “Research has shown that including cultured dairy products in your diet may have health benefits including increased immunity, improved digestion and regularity, decreased inflammation, decreased risk of cancer (colon, bladder, breast), and fresher breath,” Routhenstein says. Kefir can be enjoyed as a drink on its own, in a smoothie, with your oats, or as a marinade, Routhenstein notes. The consistency is thick like yogurt, and it can be a delicious yogurt substitute.
If you’re vegan or if you simply don’t like dairy, there are other calcium-rich food options for you. One option is seeds, says Sunny Brigham, a board-certified clinical and integrative nutrition specialist. “Chia, sunflower, and poppy seeds are great little calcium powerhouses,” Brigham says. An ounce of chia seeds contains about 18 percent of your RDA, and they’re also a great source of protein. Sprinkle some over your oats or salad or have some in your smoothies.
Leafy greens are another vegan-friendly calcium-rich food. Spinach, chard, and beet greens are high in calcium, but they’re also high in oxalates, says Brigham. As mentioned earlier, oxalates prevent calcium absorption. “I still tell people to eat them because you get tons of other nutrients from these foods and you could still absorb calcium from them,” she notes. For maximum calcium absorption, you should go for leafy greens that are low in oxalates. This includes the vitamin-rich kale, bok choy, and collards, Brigham notes.
The edible bones in sardines make it an excellent source of calcium. It also contains vitamin D, says Brigham. A single serving of sardines contains about 33 percent of the RDA for calcium.
Brigham notes that calcium is often used as a binding agent in the process of making tofu. As a result, tofu is a great source of calcium, with one half-cup serving offering 25 percent of your daily calcium needs. Consider replacing a meat serving with tofu every so often.
According to the National Osteoporosis Foundation, there are a number of foods fortified with calcium that could be a great addition to your diet. This includes plant-based milks like almond milk, soy milk, or rice milk; juices; oatmeal; and cereal.
Can supplements provide all the calcium my body needs?
If you’re not a fan of the above-mentioned foods, you might be tempted to take a calcium supplement instead. This isn’t the best idea. Brigham points out that supplements can’t supply all the calcium you need—and they might lead to some adverse health effects. [pullquote align=”center”]“The best place to get calcium is through food sources.” —Sunny Brigham[/pullquote] “The best place to get calcium is through food sources,” says Brigham. “There are studies that show excess supplemental calcium can increase kidney stone formation, but increased calcium from food sources [is] kidney protective. A few other studies have shown that high calcium supplementation has led to hardening of the arteries, yet again the same can’t be said for food.“ Routhenstein agrees. “Studies have shown a link with supplemental calcium intake and prostate cancer and with cardiovascular disease,” she says. “I recommend trying to get your daily dose through foods mentioned above instead.” That said, Brigham sometimes advises her clients to take calcium supplements. “These are usually low amounts of calcium that are paired with other supplements to increase absorption in the correct locations,” she says. As always, it’s important not to take supplements without speaking to a health practitioner first. If you’re considering taking a calcium supplement, speak to your doctor and don’t exceed the recommended dosage. There are so many calcium-rich food sources that it’s easy to get enough calcium from one’s diet alone—even if you’re lactose intolerant or vegan!