The concept of dynamic duos like Sherlock Holmes and Watson, or trios such as The Three Musketeers, doesn’t just apply to entertainment. It’s also relevant to your diet. That’s because when certain vitamins, minerals, or phytonutrients, are consumed together, they have a more powerful effect on your health than when they’re eaten alone—a concept called nutrient synergy.
In some cases, consuming certain nutrients together enhances the body’s ability to absorb one or the other; in other instances, the nutrients can have additive effects. This biochemical synergy can boost the functioning of the nervous system, and improve cardiovascular health, respiratory and musculoskeletal systems, and the immune response.
“It’s always existed but we’re just discovering the importance of nutrient synergy—the idea that the whole is more impactful than the sum of its parts,” says Keith Ayoob, a dietitian in New York City and an associate professor emeritus of pediatrics at the Albert Einstein College of Medicine. “With nutrient synergy, when you combine nutrients in the proper amounts, they’re more useful to the body than either one is by itself.”
A study published this year in the American Journal of Clinical Nutrition, for example, found that when people consume a healthy fat (such as olive oil) along with foods that are rich in beta carotene—carrots or sweet potato—or lycopene which is found in tomatoes, the fat increases the bioavailability of these health-promoting phytochemicals.
[Many of these power nutrient pairings occur in Mediterranean cooking. Read about why the Mediterranean diet has stood the test of time.]
Other studies have found that pairing black pepper and turmeric increases the absorbability of turmeric’s active ingredient, curcumin, by 2,000 percent. And research has found that when magnesium is consumed with vitamin D, the mighty mineral helps activate vitamin D in the body so that it can positively influence bone growth and maintenance.
“Some nutrients are just better together,” says Wendy Bazilian, a nutritionist and a public health consultant based in San Diego. “It’s like one plus one equals three because they enhance each other.”
Here’s a look at six dynamic nutrient combos that have synergistic effects.
Vitamin C and iron
The synergistic effect: The human body easily absorbs iron present in meat, poultry, and seafood. But the iron in plant foods is more difficult to extract.
“Vitamin C helps liberate iron from plant-based foods and make it more absorbable,” Ayoob says. This matters because your body requires sufficient iron for proper growth and development and because the mighty mineral is needed to make hemoglobin, a protein in red blood cells that carries oxygen to every cell in your body and brain.
Insufficient iron can trigger iron-deficiency anemia, including weariness, lethargy, and issues with concentration and memory. A shortage of iron also reduces the immune system’s ability to fight off infections. In recent years, the power of this nutrient pair has been so well supported by randomized, controlled trials that a recent review published in 2022 in the journal Nutrients concluded that women with iron-deficiency anemia should increase their intakes of iron and vitamin C.
How to bring them together: For breakfast, have a bowl of iron-fortified cereal with sliced strawberries or kiwi fruit. For lunch, make a spinach salad with black beans, red pepper strips, and tomato slices. Or, stir-fry shrimp, broccoli florets, mushrooms, and sesame seeds, and call it dinner.
Consuming 25 milligrams of vitamin C, the amount in ¼ cup of broccoli, will double the absorption of iron present in this vegetable, says Joan Salge Blake, a registered dietitian and nutrition professor at Boston University.
Calcium, and vitamins D and K
The synergistic effect: You probably know that calcium and vitamin D are important for building and maintaining strong bones. But you may not realize how they interact or how vitamin K contributes to this mission.
“Vitamin D helps you absorb calcium from your diet and vitamin K helps lay calcium down in the bone,” explains Bazilian. The positive trio can help protect people from osteoporosis and reduce their risk of fracturing a bone. And because vitamin K helps direct calcium to where it belongs in the bones, it helps keep it from accumulating in the arteries where it can lead to blood clots.
How to bring them together: Make an omelet with eggs, spinach, mushrooms, milk, and cheese, or a smoothie with plain yogurt, fortified oat milk, blueberries, and a tablespoon of tahini. Prepare a salad with raw kale, roasted soybeans, and canned sardines, and lightly drizzle it with soybean oil before tossing it.
[Read more about why you probably aren’t getting enough vitamin D.]
Vitamins C and E
The synergistic effect: Both vitamins have strong antioxidant properties which means they help protect cells from damage caused by pollutants, exposure to ultraviolet rays, and other sources of unstable molecules called free radicals. But they do so in different ways. Vitamin E neutralizes free radicals and vitamin C removes them before they can damage cells.
In other words, “they tag-team each other as antioxidants,” says Bazilian. In addition, a study in a 2020 issue of the journal Nutrients found that boosting intake of vitamins C and E reduced pain in people with fibromyalgia.
How to bring them together: Have a bowl of sliced strawberries and kiwi fruit, topped with sunflower seeds and chopped almonds. Make a salad with raw spinach leaves, tomato slices, red pepper slices, and a vinaigrette dressing. Stir-fry broccoli and cauliflower florets with peanuts and sunflower oil.
Vitamins B6, B12, and folate (B9)
The synergistic effect: This trio of B vitamins plays a vital role in reducing high levels of homocysteine, which are associated with a greater risk of cardiovascular disease.
In a study in a 2023 issue of JAMA Network, researchers tracked the intake and blood levels of folate, vitamin B6, and vitamin B12 and the incidence of metabolic syndrome—a cluster of conditions including high blood pressure, high blood sugar, abnormal cholesterol levels, and excess belly fat that increase the risk of heart disease, stroke, and type 2 diabetes—among 4,414 adults. Those with the highest intake of these three B vitamins had a significantly lower incidence of developing metabolic syndrome over a 30-year period.
Together this threesome also helps protect brain health and proper neurological function. “If you get enough of these together, it seems to slow down cognitive decline—it’s a long game,” Ayoob says.
How to bring them together: Have a bowl of fortified cereal with sliced banana and low-fat milk. Make a big salad with spinach, avocado, chickpeas, cooked bulgur, and a sprinkling of nutritional yeast. Or, have broiled sockeye salmon with asparagus and baked winter squash.
Potassium, magnesium, and calcium
The synergistic effect: Together these three minerals lower blood pressure, dilate blood vessels, and “help with electrolyte balance, which is hugely important for proper nerve function,” Ayoob says.
In a study involving 16,684 adults, published in a 2022 issue of Nutrition Research and Practice, researchers found that people who had a higher intake of potassium, magnesium, and calcium had a lower risk of developing high blood pressure over a seven-year period—which in turn reduced the risk for heart disease, stroke, and even a particular eye disease.
The three minerals also help regulate heart rhythm and fluid balance in the body. An additional perk, according to a 2023 study in PLOS One, found that getting enough calcium, potassium, and magnesium, may help protect adults ages 40 and older from developing glaucoma.
How to bring them together: Make a pot of oatmeal, using milk instead of water, and top it with pumpkin seeds, chia seeds, and banana slices. Add chopped spinach to your lentil soup and grate some cheese on it. Have a baked potato topped with plain yogurt or cottage cheese and cooked broccoli florets.
Vitamin E and selenium
The synergistic effect: While this is a newly discovered combo, mounting research supports the ability of these nutrients to work together as potent antioxidants to protect cells from damage.
“They help support immune cells and the function of immune cells—and they appear to enhance one another but the mechanism isn’t clear,” says Lona Sandon, an associate professor of clinical nutrition at the UT Southwestern Medical Center in Dallas. What is clear, “Vitamin E can help regenerate selenium as it gets used as an antioxidant.” What’s more, a 2021 study found that when they’re consumed together, vitamin E and selenium can control allergy symptoms and reduce airway inflammation from asthma in mice.
How to bring them together: Make your own trail mix with almonds, dried fruits, and Brazil nuts. Bake or roast halibut and serve it with cooked broccoli and brown rice. Make a smoothie with spinach, plain yogurt, kiwi slices, green grapes, and a drop of sunflower oil.
Real food. Not supplements.
Keep in mind that all of these pairings relate to the presence of these nutrients in foods, not supplements.
Think of it this way: “It’s like going to the symphony—the first violinist is magnificent but when you put the whole orchestra behind the first violinist, it makes something magical,” Salge Blake says. “They work well by themselves but when they’re combined, the effect is even better.”
[Read more about how certain foods lower your risk of disease.]