For generations we’ve been told we should drink milk — it’s a good source of calcium, “they” always say. But why do we need calcium to function? And what are foods high in calcium other than milk?
Actually, there are tons of calcium-rich foods besides cow juice, including plenty of nondairy sources of calcium. In fact, if you’re eating the right foods, you can get what you need on a plant-based diet.
Read on to find out more about calcium’s function in the body and how to increase your consumption of the mineral naturally.
What Is Calcium?
Calcium is the most abundant mineral in the body, says Krista Maguire, RD, CSSD, nutrition manager for Openfit. The vast majority of it — about 99 percent — is stored in our bones and teeth. The matrix of bone is comprised of calcium and phosphate, which is why both are so crucial for bone health, says Lisa R. Young, Ph.D., RDN, adjunct professor of nutrition at New York University.
As for the other 1 percent: Calcium also binds to certain proteins in blood, muscle, and intercellular fluids, and is then carried from one cell to another to deliver messages concerning muscle contraction, nerve conduction, and the secretion of hormones and enzymes. A huge part of this messaging involves relaxing the walls of blood vessels, Young says, which is why calcium is thought to help promote healthy heart function.
The most well-known benefit of calcium is that it helps prevent osteoporosis. “Research shows that supplementing with calcium after menopause may reduce or prevent loss of bone density; however, combining it with other agents such as vitamin D, estrogen, or calcitonin can produce small increases in bone density,” Maguire says.
Even though the effect comes way down the road, it’s crucial to keep bone health in mind early in life. “It’s especially important to not skimp on calcium in the younger years and teenage years when maximal bone growth occurs,” Maguire adds.
The same goes for those losing significant amounts of weight. Typically, bone mineral density drops along with the pounds, but consuming enough calcium in combination with strength training can help offset this effect and keep your bones healthy and strong for your new frame. Maguire notes there’s even some research — though limited and potentially contradictory — that suggests increased calcium counts may hasten weight loss.
Because of its effect on blood vessels, calcium is also necessary to help support the cardiovascular system. And Maguire says some research suggests that keeping your calcium levels up can help with certain minor PMS symptoms.
How Much Calcium Should I Get Per Day?
The recommended daily amount (RDA) of calcium spikes during adolescence, but starting at 19, men and women should aim for 1,000 mg per day. Women over 50 and men over 70 should kick it up to 1,200 mg per day as their bones naturally start to lose density. Ideally, consumption is spread out over the course of the day, Young says.
“All you need is 2–3 servings of dairy along with greens, broccoli, and almonds to meet the RDA of calcium,” Young adds. But according to the USDA, while most people already get enough of the mineral from food, roughly 43 percent of Americans — and 70 percent of postmenopausal women — take calcium supplements.
What happens if I have a calcium deficiency?
You won’t really notice fluctuations in calcium on a weekly or even monthly basis, Maguire says. For the most part, your body handles dips and spikes in calcium intake by self-regulating.
“Calcium in the blood is tightly regulated. If it falls low, calcium from bone is recruited, and if it’s high, then excess is stored in the bones,” Maguire explains. “However, there are times when blood calcium isn’t naturally regulated, and this is usually due to a disease state such as renal (kidney) failure, or could be linked to the use of certain medications.”
If you aren’t getting enough calcium over an extended period of time, you may run the risk of easier fractures, usually of the wrists, spine, or hips, Maguire adds. Protracted periods without enough calcium can increase your risk of osteopenia (the early stages of osteoporosis) or osteoporosis down the road, Maguire says.
Are there side effects from getting too much calcium?
The only way you’re likely to get too much calcium is via excessive supplementation — and even then it’s unclear if anything bad will happen, Young says.
Your best bet: Try to get most of your calcium from natural, dietary sources. And if you need a supplement, limit it to 500 mg max, except as recommended by your healthcare provider. Your cumulative calcium intake — that’s the amount from food, drinks, and any supplements — should still fall within the RDA, she adds.
Best Food Sources of Calcium
A quick review of what people are searching for online reveals that many of them think otherwise nutrient-dense foods like eggs and bananas contain appreciable amounts of calcium, or at least they want them to. Those people will be disappointed, but there are plenty of other calcium food sources.
Calcium: 325 mg | Serving size: 3 oz.
One serving of canned sardines delivers 30 percent of your RDA of calcium. That same serving will also provide 27 percent of your RDA of vitamin D, 31 percent of iron for men/14 percent for women, and a whopping 316 percent of B12, as well as 21 grams of protein.
Calcium: 482 mg | Serving size: 1 cup, fortified
If you’re lactose-intolerant or vegan, you can still drink your calcium: Unsweetened, fortified almond milk packs 48 percent of the RDA — more than cow’s milk — in one 8-oz. serving, and can also contain healthy doses of vitamins A and D, depending on the brand.
Calcium: 364 mg | Serving size: 1 cup, fortified
Many orange juice brands now add calcium, as well as vitamins like A, D, and E, making OJ a reliable source of many nutrients. One cup delivers a third of the daily allowance of calcium. And before you get too freaked out by the label, just know: “’Fortified’ doesn’t necessarily mean processed — it just means a nutrient has been added,” Young reassures.
Calcium: 340 mg | Serving size: 1 cup, fortified
Fortified soy milk will deliver anywhere from 340 mg to 450 mg of calcium per cup, depending on the brand. It may also be fortified with other nutrients, including vitamin A, vitamin D, B12, folate, phosphorus, potassium, riboflavin, and magnesium.
Calcium: 314 mg | Serving size: 1 cup (1% milkfat)
An 8-oz. glass of one-percent milk boasts 31 percent of most adults’ daily calcium needs. Milk also contains phosphorus and magnesium, which help the body absorb and use calcium. Most milk is further fortified with vitamin D, which is needed by the body to use calcium.
Calcium: Varies | Serving size: 1 oz.
All cheese is a great calcium source option, Young says. (Plus it’s also loaded with protein and B12.) Parmesan is definitely the highest, offering 336 mg per 1-oz. serving. Next comes Swiss (252 mg), provolone (214 mg), Monterey (211 mg), Muenster (203 mg), cheddar (201 mg), Colby (194 mg), and mozzarella (163 mg).
Calcium: 253 mg | Serving size: ½ cup, firm, raw
In addition to its value as a protein and iron source, a serving of soybean-derived tofu boasts 25 percent of your daily recommended intake of calcium. And if you can find it fortified with calcium sulfate, that value vaults up to 861 mg or 86 percent of the RDA.
Calcium: 230 mg | Serving size: 7 oz.
“Greek yogurt and milk are very high sources of calcium,” Young says. The National Institutes of Health agrees, calling dairy products the best source of the mineral. A seven-ounce serving of Greek yogurt offers roughly 23 percent of most adults’ daily intake. Bonus: It’s also a stellar source of protein and B12.
Calcium: Varies | Serving size: ½ cup, cooked
Leafy greens are a great vegan calcium source in addition to all of the phytonutrients presaged by their dark color. Collard greens offer the most at 134 mg calcium per serving, followed by spinach (122 mg), turnip greens (99 mg), and kale (88 mg).
Calcium: Varies | Serving size: 1 Tbsp.