Beneficial Nutrient Combinations 

Essential nutrients like vitamin D, iron, calcium, vitamin C, and magnesium are just that—essential for maintaining a number of life-sustaining functions, and thus essential for life. For this reason, it is imperative that we obtain sufficient amounts of these nutrients through the foods we eat and/or the supplements we consume.¹

Interestingly, because many vitamins and minerals interact at a chemical, biochemical, or physiological level certain nutrient pairings can actually yield greater benefits than when taken in isolation.² In other words, the combination of certain nutrients can enhance each other’s absorption, and may even have synergistic effects. Score!

In this article, we review some of the most well-established and important nutrient combinations you can use to your body’s advantage.  

Vitamin D and Calcium: Musculoskeletal Dynamic Duo

A nutrient interaction that many people could benefit from exists between calcium and vitamin D—two essential nutrients with important roles in musculoskeletal health.³ This is because, in addition to its vast array of other health benefits, vitamin D promotes calcium absorption in the gut and regulates calcium levels in the blood.³

In fact, without enough vitamin D the human body cannot form sufficient amounts of the hormone calcitriol (the active form of vitamin D), which can, in turn, lead to insufficient calcium absorption and deficiency.⁴ When calcium status is low, the body must take calcium from stores in the skeleton, which not only weakens existing bones but prevents the formation of strong, new bones.⁵ Given calcium’s dependence on vitamin D status, adequate vitamin D consumption is extremely critical. 

Unfortunately, a number of factors (e.g., use of sunscreen, dark skin pigmentation, lack of sun exposure, etc.) can affect the body’s ability to synthesize vitamin D and lead to issues of deficiency.^6,7 As a result, individuals with poor vitamin D status are not only vulnerable to the consequences of vitamin D deficiency, but also those associated with poor calcium status. 

While it is relatively easy to get sufficient amounts of calcium from the foods we eat (e.g., dairy milk, cheese, soy and oat milk, yogurt), unless you are getting sufficient levels of daily vitamin D (~600 mg), your calcium status will likely suffer. Unfortunately, vitamin D is naturally present in very few foods, thus taking a vitamin D supplement (especially during the winter months) is often recommended.⁸

Magnesium and Vitamin D Enhance the Other’s Absorption

Another one of vitamin D’s favorite companions appears to be the essential mineral magnesium. For those of you unfamiliar with magnesium’s many health benefits, this macro-mineral is involved in over 600 of the body’s biochemical reactions and plays important roles in musculoskeletal, cardiovascular, and nervous system health.^9–11

Unfortunately, roughly two-thirds of Americans are deficient in this important mineral.¹² In addition to consuming foods rich in magnesium or taking a magnesium supplement, research suggests that an effective way to enhance magnesium status is to maintain optimal vitamin D levels.¹³ What’s more? Maintaining optimal magnesium levels has a similarly beneficial effect on vitamin D status.¹⁴ (Well played, mother nature). 

So, what makes these two nutrients so compatible? An important clue as to the nature of their mutually beneficial relationship is that magnesium is a cofactor for the biosynthesis and activation of vitamin D and regulates the activity of critical enzymes involved in vitamin D metabolism.¹⁵ Thus, a deficiency in magnesium is going to negatively affect vitamin D status, whereas sufficient magnesium can help improve vitamin D levels. 

Support for their mutually beneficial relationship is evidenced in research showing that vitamin D supplementation can improve blood levels of magnesium and that supplementing with magnesium can improve vitamin D levels.^16,17

Also of import, research shows that deficiencies in both vitamin D and magnesium can increase an individual’s risk of cardiovascular disease, metabolic conditions, and suboptimal skeletal health.^17,18 For all these reasons, ensuring that you receive adequate magnesium and vitamin D from food sources or supplements is essential. The fact that these two important nutrients seem to enhance the other’s absorption provides further incentive to seek them out. 

Vitamin C Helps Iron Absorption

Another vitamin and mineral interaction with important benefits for health exists between iron and vitamin C. Iron serves many essential functions, including the very important tasks of transporting oxygen throughout the body and maintaining a healthy immune response.^19,20 Vitamin C (ascorbic acid) is similarly essential, and well-known for its antioxidant and immune-promoting functions.²¹ Another benefit of vitamin C is that it naturally enhances iron absorption—particularly iron from plant-based sources (i.e., nonheme iron), which are less bioavailable than heme sources from meat, fish, and poultry. In fact, research finds that the absorption of iron from nonheme sources such as leafy greens, nuts, seeds, and legumes is directly proportional to the quantity of ascorbic acid present in a meal.²²

For this reason, finding ways to incorporate foods high in vitamin C (e.g., citrus fruits, tomato, berries, cantaloupe, broccoli) with iron-rich meals is especially important for individuals at risk of iron deficiency, such as young children, pregnant and menstruating women, vegetarians, and the elderly.^23,24 Another option is to pair iron-rich foods or supplements with a vitamin C supplement. 

Vitamin D and Omega-3s Fat-Soluble Friends

Another nutrient relationship worth discussing is the one between vitamin D and omega-3 polyunsaturated fatty acids (ALA, EPA, and DHA). Vitamin D is a fat-soluble vitamin and is absorbed and transported in a manner similar to that of fats.²⁵ For this vitamin to be absorbed, it needs to be emulsified into micelles that contain cholesterol, phospholipids, and fatty acids.²⁶

Although clinical research to determine whether omega-3 fish oil increases absorption of vitamin D is currently lacking, numerous studies indicate that combining vitamin D with a source of fat can improve its absorption and utilization within the body.^27,28 Thus, a prudent (and easy) way to increase your uptake of vitamin D may be to combine it with a meal rich in EPA and DHA, or your daily omega-3 supplement. At the very least, you are getting the vitamins you need, and the fatty acids your body requires for optimal cellular and foundational health.²⁹

In closing

Consuming a variety of whole foods is a great way to ensure you’re receiving the essential nutrients you need for optimal health and wellness—especially if the nutrients involved interact to enhance each other’s absorption. While attaining these nutrients from foods is the gold standard, supplements can help fill any nutritional gaps that may be lacking in your diet, and offer individuals with nutrient deficiencies the means to raise their levels quickly and efficiently. We encourage you to speak with your personal health professional about other nutrient combinations that would be of benefit to you.