3 Vitamins and Minerals to for Better Absorption

Certain nutrients are more effective together than on their own. It’s called synergy. This is why calcium-rich milk is often fortified with vitamin D. Vitamin D enhances calcium absorption. It’s also why iron supplements often have added vitamin C. Vitamin C enhances the absorption of non-heme iron. How cool is that? 

You’ve surely heard nutrition pros tout the benefits of eating well-rounded meals, and this synergism is partly why. The different nutrients in fruits, veggies, proteins, dairy, grains and fats work together to support overall health. That said, there are certain vitamins and minerals that are especially important to eat together. We spoke with dietitians to share the vitamins and minerals you should pair together for better absorption.

1. Iron and Vitamin C

“Research shows that taking vitamin C (also known as ascorbic acid) along with iron may improve iron status by ‘holding hands’ with the iron until the iron is ready to be used by the small intestine,” says Kinga Portik-Gumbs, RDN, LDN. Vitamin C converts the iron into a more absorbable form and counteracts compounds that hinder iron absorption. For example, one study found that eating an iron-rich meal with 1000 mg of vitamin C increased iron absorption from 0.8 to 7.1%.

This is most helpful when consuming non-heme iron—the kind found in plant foods like beans and dark leafy greens. Our bodies don’t absorb non-heme iron as well as they do heme iron, which is found in animal foods like meat. “This can work when taking iron supplements, as well as eating iron-containing foods,” explains Jamie Lee McIntyre, M.S., RDN, CD-N. Just be sure to eat them at the same time. Separating your vitamin C and iron intake isn’t as effective for absorption.

Some examples include taking your iron supplement with a glass of orange juice, combining beans with bell peppers or eating dark leafy greens with citrus fruits.

2. Vitamin D and Calcium

“Vitamin D plays a pivotal role in calcium absorption and utilization once in the body,” says Shelley Balls, MDA, RDN, LDN. Studies show that people with healthy vitamin D levels absorb calcium much more efficiently. Unfortunately, most Americans don’t meet the recommendations for vitamin D intake, and about 40% of Americans have low blood levels of vitamin D.

Both vitamin D and calcium are important for building strong bones. When your body doesn’t have enough calcium and vitamin D, it puts you at higher risk of developing osteoporosis and other bone-related issues. “Calcium isn’t just for bones—it’s also involved in muscle contraction, nerve signaling, and hormone release,” adds Jennifer Pallian, BSc, RD.

“Food sources of calcium include dairy products, canned fish, leafy greens, tofu and fortified foods. Vitamin D is found in fatty fish, egg yolks and fortified dairy as well as fortified plant-based milks,” says Pallian. Some vitamin D and calcium combos to try are fortified milk and orange juice, salmon with leafy greens and supplements containing calcium and vitamin D.

3. Magnesium and Vitamin D

If you have low vitamin D, you may want to pair a vitamin D supplement with magnesium. 

“Magnesium is needed by enzymes in the liver and kidneys to convert vitamin D to its active form. Conversely, low vitamin D levels may affect magnesium absorption. The two nutrients depend on each other,” says Lisa Andrews, MEd, RD, LD.

These nutrients are essential for maintaining bone health, immune function, muscle and nerve health, blood pressure regulation and blood sugar control. Plus, “A recent study found that magnesium and vitamin D impact insulin sensitivity and may help improve blood sugar control,” says Andrews. The study found that taking vitamin D or magnesium supplements alone wasn’t effective, but taking the two together helped improve blood sugar control in participants with diabetes.

“Rich dietary sources of magnesium include nuts, seeds, legumes, whole grains and green leafy vegetables. Given the interconnected nature of magnesium and vitamin D, ensuring sufficient intake of both is crucial for optimal physiological function and long-term health,” says Pallian. Depending on your nutritional needs, you can take them together as supplements or lean on food sources. Some food pairings to try include salmon with leafy greens, vitamin D-fortified cereals with nuts or eggs with black beans.

Tips to Optimize Nutrient Absorption 

Pairing certain nutrients together is one way to improve absorption, but there are a few other considerations. Especially when taking supplements, speak with your healthcare provider for personalized advice based on your nutrient needs, health conditions, medications and other supplements.

• Consider the timing. Certain nutrient pairings need to be consumed at the same time, while others can be spread throughout the day. For example, it’s important to take iron and vitamin C simultaneously, but vitamin D and calcium can be spaced out.
• Consider the dosage. Especially if you’re taking a supplement, it’s important to ensure you take a dosage that’s appropriate for your age, sex, pregnancy and lactation status and dietary intake. You may also need to consider the ratio of one nutrient to the other for optimal absorption. 
• Speak with a healthcare provider for individualized guidance. Before starting a new supplement, speak with your healthcare provider for individualized guidance. They can determine whether it’s safe and worthwhile for you to take the supplement(s). They can also recommend an appropriate dosage.
• Eat well-rounded meals. For optimal nutrient absorption and general health, eating well-rounded meals is a good rule of thumb. Incorporating whole grains, fruits, vegetables, lean proteins and healthy fats ensures you’ll get a variety of macro and micronutrients to support your health. 

The Bottom Line

Specific vitamins and minerals work best as a team. They rely on each other for optimal absorption. So try pairing non-heme iron with vitamin C, magnesium with vitamin D and calcium with vitamin D. You can purchase supplements with these combos, take separate supplements, or get them from complementary foods. The best option for you depends on your nutrient status, dietary intake, health conditions, and more, so speak with a healthcare provider for individualized guidance on the best approach for you.