Multivitamins are polarising in the world of nutrition. Some people love them; others are very skeptical.

So, what do you base your opinion on? What should you think?

We’re going to cover some fundamental questions: do multivitamins work? Do they help your immune system? What should you look for in a multivitamin—and how should you use them?

There’s a lot to be said on either side, so we’re going to get a clear picture today so you can decide for yourself if the costs and benefits suit you.

The Basics: What are Multivitamins?

A multivitamin is obviously a mixture of multiple vitamins in a single tablet or liquid. The idea is that it provides you with a wealth of vitamins that your body needs, supporting your overall health and wellbeing.

The idea is obviously to make a daily habit of a multivitamin. It’s marketed as a way of making sure you’re up to scratch on the most important vitamins—and sometimes minerals, for your health and wellbeing.

How Does it Work?

1. For: What the vitamins do

When you look at a standard multivitamin supplement, even the cheapest you can get, it’s going to focus on the essential lettered vitamins that your body needs.

These are essential because your body can’t just produce them out of other things—you need to consume them.

These are usually the key essential vitamins:

  • A
  • B (1, 2, 3, 6, 7, 9, and 12)
  • C
  • D
  • E
  • K

These are the most important and, if everything was perfect with your multivitamin, we could definitely say these improve the immune system.

While there are many factors, key vitamins like A, C, D, and E are closely related to immune function and health.

You’ll also see significant improvements if you go from deficiency to healthy levels of B6, B9, and B12, which are crucial for cellular metabolism and wellbeing.

Properly fuelling your immune system is an area that doesn’t get much attention but affects your ability to regulate your wellbeing across organs.

The thing to remember is that the difference is between deficiency and sufficiency.

More vitamins don’t mean better health: you need to get the amount to fuel your immune system and other processes. Topping up is the goal, not just maxing out how many you can get in a day.

2. Against: The problem with multivitamins

On the other hand, skepticism has appeared around multivitamins for two main reasons. We’ll call these the purity of a multivitamin and the bioavailability of the sources.

Purity is a problem when we look at the difference between labeling and actual ingredients.

It’s cheaper to underdose most supplements, and multivitamins aren’t immune: they can be under 50% of what they say or up to 30-100% more than labeled.

Bioavailability refers to how much of the thing you digest and take up compared to what is in the product. You can take a tablet and not absorb any of it—and in multivitamins, there are some concerns for this bioavailability.

The Big Question: Do They Work?

The real question of whether you’ll see improvements in your immune system depends on your diet and your lifestyle, too.

They can be a way of improving your daily vitamin intake, which can itself improve your immunity if you’re deficient. It’s not a case of just slamming down multivitamins to supercharge your immune system.

However, you need to stay aware that you’re dealing with a possibly underdosed product. This doesn’t mean avoiding a multivitamin: it means adjusting your expectations and maybe even what kind of product you’re buying.

What is the cost and benefit of your multivitamin? Would you be okay with your expensive multivitamin being underdosed? What about a cheap one from your local supermarket? The question is how much of your multivitamin you’re getting the benefit of.

I like to use a multivitamin as a just-in-case. I don’t expect it to make a significant difference, but I do get the peace of mind that I am paying very little for a bit of nutritional support. I also like an effervescent version to stack the habit with my first glass of water in the day.

Summary & Key Points

So, yes, multivitamins seem to be one way of improving your immune system – though perhaps not as much as the sellers would like you to think.

We should stay skeptical about the overall benefits they offer: don’t rely on them as a crutch for the diet.

In the meantime, you should consider other areas. Are you using a multivitamin but sleep-deprived? Are your exercise and rest schedules supporting your immune system? Are you managing the lifestyle stressors that suppress your immune function?

The point isn’t to grill you: it’s that multivitamins are only one part of the diet, which is only one factor in immune function.

You can’t treat a multivitamin like a cure-all to “fix” your immune system. It’s a part of a patchwork of different things that shifts your immune function up or down.


  1. Contributing micronutrients for immune function:
  2. Issues surrounding multivitamins:
  3. Multivitamin Dosages: