It’s important to get your nutrients in, but keeping a healthy diet doesn’t always mean you’re getting all of the nutrients you need. The bioavailability, or the body’s ability to absorb nutrients from a food, is as important as the nutrient content itself. If our bodies can’t absorb the nutrients, it’s as though we never ate them at all. Many vitamins and minerals have strange interactions that can either enhance or hinder the other’s effects—so depending on the food pairings you concoct in your kitchen, you may be boosting or missing out on the benefits of those healthy foods. To get the full nutrient bang for your buck and prevent wasting any of the good stuff, here are 13 nutrient combinations that you should either work in together or eat separately for maximum absorption:
THE ‘DO’ LIST
1. Vitamin C and Iron
The body absorbs iron much more effectively when vitamin C is present as well. In addition to the absorption factor, vitamin C also helps to synthesize red blood cells. This is another connection between iron and vitamin C because iron is the main part of hemoglobin, which is found in the red blood cells. It is good to note that iron from animal foods, such as beef, is much more absorbable than iron from plant foods, like spinach and legumes. This is because other factors in plant-based sources can inhibit your uptake of iron—like oxalic acid in spinach. To best absorb plant-based iron, it is much more necessary to pair it with a source of vitamin C, which helps to break down the iron into a form that the body can more easily absorb.
- Good sources of iron: lean and organ meats, leafy greens, legumes and quinoa
- Good sources of vitamin C: citrus fruits, bell peppers, kiwi, broccoli, tomatoes, berries and pineapple
2. Vitamin D and Calcium
Calcium can only reach its full bone-building potential if your body has enough vitamin D. Vitamin D helps absorb, carry and deposit the majority of calcium in our body into our bones and teeth. If you’re short on vitamin D, your body won’t be able to carry the calcium into the bones to be absorbed and stored. So even if you’re taking in enough calcium, it could be going to waste if you’re deficient in vitamin D.
- Good sources of vitamin D: sun exposure (at around noon), fatty fish, eggs, dairy, mushrooms, tofu, dairy alternatives such as almond milk and soy yogurt
- Good sources of calcium: dairy products, kale, bok choy, cabbage, broccoli, tofu and soy
3. Inulin and Calcium
Studies show that inulin enhances calcium absorption to support bone health and prevent osteoporosis. This would be beneficial for people who are younger, as it helps strengthen bones to help them once they approach an older age and are more susceptible to osteoporosis.
- Good sources of inulin: bananas, asparagus, leek, onion and garlic
- Good sources of calcium: dairy products, kale, bok choy, cabbage, broccoli, tofu and soy
4. Healthy Fats and Fat Soluble Vitamins (A, D, E, K)
Fat-soluble vitamins—vitamin A, vitamin D, vitamin E and vitamin K—will not dissolve in water. Instead, fat-soluble vitamins absorb best when taken with higher-fat foods. Once absorbed into the body, fat-soluble vitamins are stored in fatty tissues and liver. The body can use these stores for future use. However, it is good to note that taking in too much of a fat-soluble vitamin may cause toxicity and adverse reactions.
Each type of fat-soluble vitamin promotes different functions in the body. Vitamin A plays an important role in maintaining healthy vision. Vitamin D aids in bone health and development. Vitamin E helps the body destroy free radicals, which are unstable molecules that can damage the cells. Vitamin K plays a role in blood clotting, which is to prevent a person from bleeding out from injuries.
- Good source of healthy fats: eggs, dairy, fatty fish, nuts, avocado, extra virgin olive oil, chia seeds, flax seeds, coconut and coconut oil
- Good sources of vitamin A: yellow, orange & red-colored produce, like peppers, carrots and tomatoes, sweet potato, squash, rockmelon
- Good sources of vitamin D: sun exposure (at around noon), fatty fish, eggs, dairy, mushrooms, tofu, alternatives such as almond milk and soy yogurt
- Good sources of vitamin E: nuts, sunflower seeds, spinach, broccoli and vegetable oils (wheat germ, sunflower, safflower, corn, and soybean oils)
- Good sources of vitamin K: leafy greens (kale, mustard greens, swiss chard, collard greens, spinach, etc), natto, brussel sprouts
5. Sulforaphane and Selenium
Sulforaphane is found to work incredibly well with selenium to boost anti-cancer effects. When these nutrients are combined, their total antioxidant power increases exponentially.
- Good sources of sulforaphane: broccoli sprouts, broccoli, cauliflower, brussel sprouts and kale
- Good sources of selenium: brazil nuts, fish, wheat germ, sunflower seeds and meats
6. Complementary proteins
Only some foods contain all the essential amino acids your body needs. These complete protein sources are often obtained from animal products like meat, poultry, fish, dairy and eggs. Other protein sources from legumes, nuts, grains and vegetables are incomplete, meaning they lack one or more of the essential amino acids needed for growth and development. So, if you’re following a vegetarian or vegan diet, pairing complementary proteins together is required to create a complete protein source to maximize nutrition and improve health.
- Good combinations of proteins: brown rice with black beans, soups/stews that include legume and grains, salads with beans and nuts/seeds, peanut butter on whole-wheat grain, hummus with whole-wheat cracker, tofu/tempeh with brown rice, yogurt with nuts
7. Red Wine and Omega 3
Studies reported that the properties and polyphenols in red wine can increase absorption of omega 3 in the body. Just remember, drinking too much is bad for your health, so stick with one glass for women and two for men.
- Good sources of omega 3: fatty fish, flax seeds, chia seeds, walnuts and soybeans
8. Green Tea and Vitamin C
A study found that citrus juices enable more of green tea's unique antioxidants to remain after simulated digestion, making the pairing even healthier than previously thought. The study found that lemon juice caused 80 percent of tea's catechins to remain. Catechins is a type of disease-fighting antioxidant that can also help with body fat reduction.
9. Steak and Rosemary
Rosemary is rich in rosmarinic and carnosic acids that stop cancer-causing heterocyclic amines from forming on cooked meat. Studies show that adding it to ground beef and other types of muscle meat before grilling, frying, broiling or barbecuing significantly reduces heterocyclic amines.
10. Turmeric and Black Pepper
Research shows that a compound in black pepper, known as piperine, significantly improves the absorption of curcumin, which is the active component in turmeric hailed for its anti-inflammatory properties, in the body. It reported that piperine enhances curcumin absorption by up to 2,000%! One study showed that it only took 20 mg of piperine to 2 grams of curcumin to elicit this response. To maximize the benefits of this powerful duo, considering adding black pepper to your golden milk turmeric tea, or in a curry, or as a dry rub for meats.
THE ‘DON’T’ LIST
1. Caffeine and Iron
Studies reported that some properties in tea and coffee can hinder absorption of iron in the body, due to the caffeine content and polyphenols found in the beverages. One study found that drinking a cup of coffee with a hamburger meal reduced iron absorption by 39%. Drinking tea, a known inhibitor of iron absorption, with the same meal reduced iron absorption by a whopping 64%. Another study found that drinking a cup of instant coffee with a bread meal reduced iron absorption by 60–90%. What’s more, the stronger the coffee or tea, the less iron absorbed. Next time you want your morning cup of coffee or tea to wind down before bed, go decaf or drink either prior to or after consuming an iron-rich meal. Stick with plain water whenever possible.
2. Iron and Calcium
Studies have shown that calcium can inhibit the absorption of iron. However, studies in which calcium intake was substantially increased for long periods shows no changes in hematological measures or indicators of iron status. This could mean that the inhibitory effect may be of short duration. Avoid calcium for 30 minutes before and after consuming iron for maximum absorption.
3. Folate and Vitamin B-12
The combination of folate and vitamin b12 is difficult to say the least—studies show that consuming a proper ratio of folate and B12 can boost health, strengthen the heart and decrease risk of Alzheimer's; however, high folate consumption can also mask a deficiency in vitamin b12. The National Institute of Health warns that it can also make the symptoms of B-12 deficiency worse, increasing the risk of permanent nerve damage and cognitive decline. Thus, maintaining a healthy amount of each is the only way to prevent a deficiency from occurring. In order to ensure that you’re not consuming excess folate, the NIH states that healthy people over the age of 19 should not take more than 1000 mcg of folate per day, while the recommended dietary allowance for B-12 in those over the age of 14 is 2.4 mcg.
- Foods that are high in folate/folic acid: legumes (especially lentils), beef liver, asparagus, eggs, leafy greens and beets
- Foods that are high in vitamin B12: organ meats, clams, fish, beef, dairy and eggs