How do multivitamins work?

How do multivitamins work?


You pop a daily multivitamin and it’s supposedly filled to the brim with all your essential nutrients for the day. How does that actually work? How can one tiny capsule contain good-for-us ingredients that are meant to typically be found in a range of foods?


The ins and outs of a multivitamin

Multivitamins are designed to fill in the “nutritional gaps” in your diet. Simply put – a multivitamin is a handy helper to give you a dose of nutrients that you may not get from food alone. For people with specific food allergies and restrictions, a multivitamin can make a real difference in their health and well-being.

The life of multivitamins in a factory starts with creating a specific formula based on nutritional needs. High-quality ingredients are carefully measured and mixed, then formed into tablets or capsules. Some tablets get special coatings to make them easier to swallow. When completed, the multivitamins are packaged, labelled and stored before being sent out to a shelf near you.

A single multivitamin can aim to contain a broad spectrum of “essential” vitamins and minerals, but there are several factors that influence how well it can meet our nutritional needs.

Multivitamins typically include essential vitamins (A, C, D, E, K, and B-complex) and minerals (calcium, magnesium, zinc, iron, etc.).


What happens when you take a multivitamin?

  • Oral ingestion: You swallow the multivitamin, which travels to your stomach and then your intestines.
  • Dissolution and breakdown: The pill dissolves in your stomach acid, releasing the vitamins and minerals.
  • Absorption: Nutrients are absorbed through the walls of the small intestine into the bloodstream. How well it’s absorbed and used by the body, can vary depending on its form and the presence of other nutrients.


Once absorbed, the nutrients travel to various parts of the body where they are involved in numerous biochemical and physiological processes. Each vitamin has specific roles. For example:

  • Vitamin A: Helps eye health, immune function and skin health.
  • B vitamins: Good for energy production, red blood cell formation and nervous system function.
  • Vitamin C: Acts as an antioxidant and enhances immune function.
  • Vitamin D: Regulates calcium and phosphorus absorption, supports bone health and modulates immune function.
  • Vitamin E: Acts as an antioxidant, protecting cells from damage.
  • Vitamin K: Essential for blood clotting and bone health.
  • Calcium: Important for bone and teeth health, muscle function, and nerve signalling.
  • Iron: Essential for oxygen transport in the blood and energy production.
  • Magnesium: Involved in over 300 enzymatic reactions, including energy production and protein synthesis.
  • Zinc: Supports immune function, wound healing and DNA synthesis.


Good to know

Multivitamins cannot duplicate the full range of nutrients and health benefits that you can get from a diet filled with real fruits, vegetables, whole grains and lean proteins. Also, taking more vitamins than necessary can cause other health problems:

  • Fat-soluble Vitamins (A, D, E, K): These vitamins are stored in the body's fatty tissues and liver. Too much can lead to toxicity. For example, extra Vitamin A can cause liver damage and birth defects, while excessive Vitamin D can lead to hypercalcemia, which affects the heart and kidneys.
  • Iron: Too much iron can cause gastrointestinal distress, liver damage and even death in severe cases, particularly in children who accidentally ingest adult iron supplements. 
  • Calcium: Excessive calcium can lead to kidney stones, impaired absorption of other minerals plus cardiovascular problems.


This article is for informational purposes only. Always check with your doctor or medical practitioner about any health concerns, before embarking on any fitness or nutrition programme, or using any medication.