Calcium is one of the most abundant minerals in the human body – and for good reason. Calcium is vital for controlling a number of body functions including muscle contractions, nerves that control heart rhythm, the action of hormones and neurotransmitters and blood clotting. Despite its importance, only a small fraction of the calcium in the body is used for these purposes. Ninety-nine percent of body calcium is found in teeth and bones where its function is to strengthen them. Inadequate dietary calcium over time can lead to loss of bone density, a condition called osteoporosis.
Calcium Absorption: You Don’t Absorb All the Calcium You Take In
With calcium playing a major role in health, it’s easy to see why it’s important to get enough of it. The best sources of calcium are dairy foods with yogurt and milk topping the list. Some of the best non-dairy sources of calcium are green, leafy vegetables, tofu, and broccoli. Some foods like orange juice and cereals are fortified with calcium, and these foods offer another way people who don’t eat dairy can meet their calcium requirements. There’s another factor that affects how much calcium your body can use – and that’s how much you actually absorb.
Most people need between 1000 and 1500 milligrams of calcium a day. Even if you’re getting enough calcium in your diet, you don’t necessarily absorb it all. Calcium absorption declines with age so by the time women reach menopause they’re only absorbing fifty-percent of the calcium they did when they were adolescents. Fortunately, there are ways to increase the amount of calcium you absorb from the foods you eat. Getting calcium by eating calcium-rich foods is best since some research shows that supplementing with calcium may increase the risk of heart disease.
Ways to Increase Dietary Calcium Absorption
One of the best ways to ensure you’re getting maximum benefits from the calcium you take in through diet is to get enough vitamin D. You need a minimum of 800 IU a day, and some experts believe it’s important to get even more. Vitamin D not only independently boosts bone health – but it also increases calcium absorption from the digestive tract, so you’re able to put more of the calcium in your diet to good use. The best source of vitamin D is sun exposure, so if you avoid the sun, you may need to take a vitamin D supplement. Talk to your doctor about this.
The composition of what you eat also affects how much dietary calcium you absorb. If you eat a diet that’s high in fiber, it can reduce the amount of calcium you absorb from food. There are other dietary components called oxalates that bind with calcium and cause more of it to be lost through the digestive tract. Foods rich in oxalates include spinach, Swiss chard, rhubarb, beets, chocolate, berries, tea, and nuts. Note that some of these foods are good for you, and you don’t want to eliminate them entirely.
Other compounds called phytates in foods such as beans, cereal husks and seeds block calcium absorption. This is usually only a problem when you’re eating calcium-rich foods at the same time as foods that contain oxalates or phytates. Spinach is a good source of calcium, but because it contains oxalates not all of its calcium is absorbed. It’s important to keep that in mind when you choose your calcium sources. Don’t eat yogurt while you’re sipping a cup of tea.
Other dietary components that reduce calcium absorption are diets high in sodium, high-protein diets rich in phosphorus, alcohol, smoking, and caffeine. People who drink soft drinks may be harming their bones due to a large amount of phosphorus these drinks contain. Another reason to give up soft drinks.
The Bottom Line?
Even if you’re getting adequate calcium in your diet, calcium absorption may be an issue. Make sure you’re getting enough vitamin D through exposure to sunlight, diet or a supplement and avoid eating calcium-rich foods with foods that are high in phytates or oxalates. Cut back on sodium, caffeine, alcohol and soft drinks to further boost the amount of calcium your body can use.
References:
Medscape.com. “Approaches to the Prevention and Treatment of Osteoporosis: Calcium and Vitamin D.
WebMD. “Calcium Supplements May Increase Heart Risk”
EMedicineHealth. “Osteoporosis and Calcium”
Related Articles By Cathe:
Calcium Absorption: How Much Calcium Are You Actually Absorbing from the Food You Eat?
Beyond Calcium: 4 Nutrients for Healthy Bones
5 Ways to Boost Dietary Calcium Absorption
