Ask a Dietitian: Can You Overdose on Vitamins?

Hi Dan, can you ever overdose on vitamins if you go above the recommended daily amount?

In short, yes, you can overdose on vitamins. As well as health bodies stating recommended daily amounts that you should be consuming of each vitamin, they also provide tolerable upper intake levels (ULs) for certain vitamins.

I say certain because not every vitamin has an UL. If you regularly consume above an UL then your risk of negative health effects (this could be short or long term) will increase.

Exceeding the UL once in a while is unlikely to be a problem because the body has processes to remove the excess, but this is for those consistently consuming above safe levels. Of course, if you were to consume significantly above an UL then you could see effects soon after consumption, but this is very rare.

Overdosing most commonly occurs through supplements. There are some supplements that have levels way above what you need, normally to try and make the supplements look more appealing with the mantra more is better.

These are pretty easy to avoid by looking at the percentages on the back of the packaging and seeing if anything has really high percentages (we're talking several times higher than 100%) and then checking against UL values. Pretty much all major multivitamins are okay because companies know to avoid exceeding UL.

Now I know what you’re thinking... Huel products are not an issue. This is because Huel products are nutritionally complete at 2000 kcal, so even if you consume more than 2000 kcal (5 meals) of Huel a day you are unlikely to exceed an UL.

There are other ways that overdosing can occur. You might have seen vitamin drips on your local high street - please please don’t have one - apart from being unregulated, they make it a lot easier to overdose because injections bypass the gut and they are only suitable in specific hospital cases. Overdosing can also occur if you have certain medical conditions or are pregnant because this can lower the general UL recommendations I mentioned above, this is something your doctor will mention to you if it applies to you.

If you’re just consuming foods then it’s really difficult to overdose on vitamins and I wouldn’t worry. When it comes to supplements a quick check can ease your concerns and so overdosing on vitamins really isn’t as exciting as you think, although if you consume too much carotene you can turn yellow and that’s kind of fun.

TL;DR

Yes you can, but unless you’re taking unprescribed high dose supplements or eating a lot of a single food, I wouldn’t worry.

Dan Clarke, RNutr

Junior Sustainable Nutrition Manager