How to Manage Your Calcium Intake
Including calcium-rich milk in your diet often is associated with preventing osteoporosis, but building strong bones isn’t as simple as eating lots of calcium. The science actually is much more complicated than that. A constellation of factors affects the amount of calcium you need from your diet as well as the amount that finally reaches — and stays in — your bones. Scientists do the best they can to estimate the effects of these factors when they issue dietary recommendations for the public.
Determining how much calcium you need
Because each person eats somewhat differently and has different lifestyle habits and genetic profiles, a person’s individual calcium needs may be somewhat different than the recommendations made for the masses. When making general recommendations, though, scientists start by making a rough guess as to how much calcium humans need. Here’s the process scientists take to estimate recommendations:
They figure that each person loses a certain amount of calcium every day.
You lose calcium through your urine, feces, and even your sweat.
They subtract that amount from the average amount of calcium you take in and absorb from your food each day.
They know the average amount of calcium people consume every day from national dietary surveys.
With that information, scientists calculate the amount of calcium most people need each day from their diets to break even, considering the daily gains and losses.
They pad that final figure a little bit, just for good measure.
Recommended levels of calcium intake for Americans vary by age and sex. Scientists (those who make recommendations) generally assume the worst, though, and try to compensate for the average American’s poor eating habits.
Nutritionists don’t really expect anyone to count the number of milligrams of calcium they eat every day. Instead, they suggest that you aim for some general meal planning guidelines. It bears repeating, though, that your individual needs vary, depending on a host of lifestyle and other factors.
Figuring how calcium relates to other nutrients
Too much sodium can rob your body of its calcium stores. Unfortunately, most people get far more sodium in their diets than what’s good for them. To help conserve your body’s calcium, read food labels and choose foods that are as low as possible in sodium. Keep your total sodium intake below 2,000 milligrams each day. A target of 1,500 milligrams is even better.
Phosphorus is a mineral that in excess can cause you to lose calcium. Meats, milk, soft drinks, and the caffeine in coffee and tea are rich in phosphorus. The effect of phosphorus on your body’s calcium stores isn’t as great as that of sodium, but it makes sense to be aware of the potential effects and to moderate your intake of high-phosphorus foods.
Even if you eliminate dairy from your diet and plan to get your calcium from other sources, you still have to be aware of other substances that can affect your calcium intake. Phytates and oxalates, for example, are in plant foods. They can bind with calcium and prevent your body from absorbing the calcium in the foods that contain them.
Your body can adapt when it needs to. In other words, depending on your dietary conditions, your body may be able to absorb more or less calcium from the foods you eat. For example, if your diet is short on calcium and you need it, your body may be able to absorb more. If you need less and you flood your body with calcium, you’ll absorb less. Your body is a smart machine. But don’t let that fact change your mind about whether you need to eat healthfully!