Good nutrition — and the way in which in our bodies absorb and process nutrients — is a much bigger puzzle than simply getting enough vitamins and minerals.

Most nutrients don’t fly solo: they interact, join forces or cancel each other out. Food is often preferable to pills or supplements because it contains a mixture of nutrients. With each mouthful we reap the nutritional rewards from their combined benefits.

The following is a list of a few of the nutrients that work in pairs. Understanding these powerful combinations may help you make the right food choices.

Vitamin D and calcium: Like most nutrients, calcium is absorbed primarily in the small intestine. If large quantities are present, the body can easily absorb it. But in smaller amounts, the mineral gets absorbed with active assistance from vitamin D. Right now, official nutrition guidelines recommend that adults get 1,000 milligrams (mg) of calcium and 400 international units (IU) of vitamin D daily. For older adults, it’s a bit more: 1,200 mg of calcium starting in your 50s and 600 IU of vitamin D starting in your 70s. To give you an idea of how much that is, an 8-ounce glass of milk contains 300 mg of calcium and, because of fortification, 100 IU of vitamin D.

There’s debate these days about whether to revise the recommendations to reduce the goal for calcium intake (or at least de-emphasize it) and raise the goal for vitamin D by recommending a daily 1,000 IU vitamin D supplement.

Sodium and potassium: About 90% of the sodium we ingest comes in the form of sodium chloride — salt, in common parlance. Although sodium is an essential nutrient that helps maintain fluid levels in the body, the average American consumes far more of it each day than he or she needs.

Too much sodium can boost blood pressure, and with it, the chances of having a stroke or heart attack. Potassium counters the harmful cardiovascular effects of a surplus of sodium by encouraging the kidneys to excrete sodium. Many studies have shown a connection between high potassium intake and lower blood pressure. In fact, the potassium-to-sodium ratio may be more important than potassium—or sodium—alone.

Almost all of us need to have more potassium in our diets and a whole lot less sodium. And the best way to do that is to load up on fruits and vegetables (prime sources of potassium) and cut back on cookies, salty snacks, fast foods, and ready-made lunches and dinners (prime sources of sodium).

Vitamin B₁₂ and folate: Vitamin B₁₂ and folate work together to support some of the most fundamental processes of cell division and replication. They also metabolize homocysteine in tandem. Folate, which is itself one of the B vitamins, depends on vitamin B₁₂ to be absorbed, stored, and metabolized. Breakfast cereals with added vitamins and minerals typically contain vitamin B₁₂, and in the United States, cereal grains are fortified with folate.

Zinc and copper: Copper and zinc, both essential nutrients, compete for absorption sites in the small intestine. If there’s a lot of zinc around, copper tends to lose out and a copper deficiency may develop. Adults are supposed to get 900 micrograms of copper daily. The daily zinc goals are 11 mg for men and 8 mg for women. Getting enough zinc can lead to a copper deficiency, so it’s important to get enough of both to keep the nutrients in balance.

Neither mineral is rare in the American food supply, so copper and zinc deficiencies aren’t something most people need to worry about. One possible source of zinc overload is, of all things, denture cream. Research has shown that using very large amounts of denture creams can lead to a copper deficiency from zinc overexposure.