Vitamin A and zinc are essential nutrients that must be consumed to maintain optimal health and physiological function. As both are considered ‘essential’—they can’t be made in the body—they must be consumed through diet.
Luckily, there is no shortage of foods that contain zinc and vitamin A, so getting your fill shouldn’t be difficult.
However, taking zinc alone may improve zinc status, but it’s not the same for vitamin A; a vitamin A deficiency often isn’t corrected by taking only vitamin A—it needs its partner in crime, zinc.
If you weren’t aware of the interaction between zinc and vitamin A, we’re letting you in on the secret. We’ll talk about what zinc and vitamin A are, their health benefits, and why you need to take them together.
Let’s get started.
What Is Zinc?
Zinc is an essential trace mineral that plays many vital roles in keeping your body healthy and running smoothly. Because your body rarely produces it, zinc must come through food or supplements to maintain levels.
As the second most abundant trace mineral in the body after iron, zinc is present in all cells and is required for the activity of over 300 enzymes involved in metabolism, digestion, function of the nervous system, immunity, reproduction, and much more 1, 2.
Zinc is needed for 3:
- Enzyme reactions
- Gene expression
- Immune responses
- Protein synthesis
- DNA synthesis
- Wound healing
- Growth and development
- Hormone production
- Epithelial integrity
- Maintain lining of reproductive organs
- Skin health
- Immune function and wound healing
- DNA synthesis and cell division
- Cognitive function
Need we say more? Based on that list alone, it should be evident that zinc is a non-negotiable part of your diet, and getting enough is beyond important. But zinc also has powerful antioxidant and anti-inflammatory properties.
Studies have found that several chronic diseases like atherosclerosis, diabetes, neurodegenerative disorders, Parkinson’s, and age-related macular degeneration (AMD) all have an underlying inflammatory and oxidative stress component, which means boosting your intake of nutrients with antioxidant properties, like zinc, is essential to protect cells against damage and inflammation 4.
If that wasn’t enough, zinc is also a major healing mineral and a staple for the immune system. It supports the proper function of the thymus gland (an organ involved in immune function) and is needed for vitamin B6 to work properly.
Zinc also affects several parts of the immune system, ranging from skin barrier function and gene regulation within lymphocytes to the normal development and function of cells mediating nonspecific immune responses (neutrophils and NK cells) 5. A zinc deficiency there will affect nearly every part of the immune system.
But here’s the thing with zinc—a deficiency isn’t always the result of a lack of dietary intake. What’s in the diet can also significantly affect how much zinc your body absorbs.
For example, phytic acid, an anti-nutrient common to plant foods, can interfere with the bioavailability of certain minerals, including zinc, thereby decreasing absorption and influencing levels.
So, what’s the solution? Ensure you’re supplementing to stay on top of your levels!
What Is Vitamin A?
The other half of the equation is vitamin A—a group of fat-soluble compounds that includes retinol, retinal, and retinyl esters 6, 7. It’s been touted as the wonder nutrient for vision, but apart from vision, it’s needed for several other critical functions.
Before we get into the details of what vitamin A does, understand the difference between the two forms:
- Preformed vitamin A (retinol)
- Provitamin A (carotenoids)
Preformed vitamin A, also known as retinol, is the active form of vitamin A that’s common to animal foods 6. Once ingested, retinol is converted to retinoic acid, retinal, and retinyl esters, the only forms of vitamin A the body utilizes immediately.
Carotenoids, on the other hand, refer to a group of 750 naturally occurring plant pigments responsible for giving many fruits and vegetables their rich hues of red, orange, and yellow.
Unlike the active form of vitamin A, carotenoids must be converted into retinol before being used 8.
But what exactly does vitamin A do? It’s involved in the following:
- Vision and eye health
- Immune function
- Reproduction
- Reducing chronic disease risk
- Skin health
- Bone health
- Growth and development
Because vitamin A is widespread use throughout the body, a vitamin A deficiency can affect multiple systems. But before you go loading up on vitamin A-rich foods and supplementing, be mindful that vitamin A is fat-soluble and stored in the body.
Overdoing it on beta-carotene may not be highly problematic, as its conversion to the active form is regulated 9.
However, consuming too much preformed vitamin A through diet or supplements can lead to hypervitaminosis A, which can cause symptoms such as nausea, dizziness, headaches, pain, and in severe cases, even death.
Why You Should Take Zinc With Vitamin A
It’s clear that vitamin A and zinc are both essential for optimal health and well-being, but most people aren’t aware that you need zinc for your body to use vitamin A.
Here are four reasons why you should be taking vitamin A and zinc together.
1. Zinc is a component of retinol-binding protein
Retinol-binding protein (RBP) is a protein synthesized in the liver responsible for transporting vitamin A from the liver to other tissues. However, hepatic synthesis of RBP depends on zinc levels.
Studies show that a zinc deficiency can suppress the synthesis of retinol-binding protein (RBP) in the liver and lead to low concentrations of RBP in both the liver and plasma 10, 11.
2. Zinc is needed to convert retinol to retinal
For retinol to be utilized by the body, it must undergo conversion from retinol to retinal—and this conversion process requires the action of zinc-dependent retinol dehydrogenase enzyme 11.
A zinc deficiency can therefore interfere with the conversion of retinol to retinal, rendering dietary or supplementary vitamin A useless.
3. Zinc helps transport vitamin A through the body
As mentioned before, retinol-binding protein is needed to transport vitamin A throughout the body, but the synthesis of RBP depends on zinc concentrations. As such, low zinc intake can impair RBP synthesis and, therefore, the transport of vitamin A throughout the body.
Studies find that a zinc deficiency has been linked to a decreased release of vitamin A from the liver. Even when adequate amounts of vitamin A are present, a zinc deficiency could contribute to symptoms of night blindness 11-13.
4. Supports immune function
Although they have different roles, zinc and vitamin A are needed to support a healthy immune system.
Vitamin A supports immunity by maintaining the health and function of your mucous barriers (eyes, lungs, gut, genitals), which are a component of your innate immune system and are required to trap bacteria and other pathogens 14.
Vitamin A also plays regulatory roles in cellular immune responses and humoral immune processes, as well as the production and function of white blood cells.
On the other hand, zinc also plays a significant role in the immune system. It’s essential for the normal development and function of cells mediating innate immunity, neutrophils, NK cells, and macrophages, as well as intracellular killing and cytokine production 15. Its role as an antioxidant also means it protects cells against oxidative damage and stabilizes cell membranes.
A deficiency of either impairs immune function and increases susceptibility to illness and infection.
Final Thoughts
Most people worry about eating a diet rich in zinc or vitamin A or supplementing. Still, few understand why it is important to get enough of both simultaneously.
A diet rich in vitamin A isn’t beneficial if you’re missing zinc, and vice versa, so focusing on both is critical.
And while loading up your diet with them is a great place to start, the easiest way to ensure you have enough of both is in a high-quality multivitamin like Performance Lab NutriGenesis Multi!
References
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- Zastrow ML, Pecoraro VL. Designing hydrolytic zinc metalloenzymes. Biochemistry. 2014;53(6):957-978.
- Prasad AS. Zinc: an antioxidant and anti-inflammatory agent: role of zinc in degenerative disorders of aging. J Trace Elem Med Biol. 2014;28(4):364-371.
- Prasad AS. Zinc: an overview. 1995;11(1 Suppl):93-99.
- Shankar AH, Prasad AS. Zinc and immune function: the biological basis of altered resistance to infection. Am J Clin Nutr. 1998;68(2 Suppl):447S-463S.
- Gilbert C. What is vitamin A and why do we need it?Community Eye Health. 2013;26(84):65.
- O’Byrne SM, Blaner WS. Retinol and retinyl esters: biochemistry and physiology. J Lipid Res. 2013;54(7):1731-1743.
- Wang XD. Carotenoids. In: Ross CA, Caballero B, Cousins RJ, Tucker KL, Ziegler TR, eds. Modern Nutrition in Health and Disease. 11th ed: Lippincott Williams & Wilkins; 2014:427-439.
- Penniston KL, Tanumihardjo SA. The acute and chronic toxic effects of vitamin A. Am J Clin Nutr. 2006;83(2):191-201.
- Smith JC Jr. The vitamin A-zinc connection: a review. Ann N Y Acad Sci. 1980;355:62-75.
- Christian P, West KP Jr. Interactions between zinc and vitamin A: an update. Am J Clin Nutr. 1998;68(2 Suppl):435S-441S. doi:10.1093/ajcn/68.2.435S
- Christian P, Khatry SK, Yamini S, et al. Zinc supplementation might potentiate the effect of vitamin A in restoring night vision in pregnant Nepalese women. Am J Clin Nutr. 2001;73(6):1045-1051.
- Boron B, Hupert J, Barch DH, et al. Effect of zinc deficiency on hepatic enzymes regulating vitamin A status. J Nutr. 1988;118(8):995-1001.
- Huang Z, Liu Y, Qi G, Brand D, Zheng SG. Role of Vitamin A in the Immune System. J Clin Med. 2018;7(9):258.
- Prasad AS. Zinc in human health: effect of zinc on immune cells. Mol Med. 2008;14(5-6):353-357.
