Whilst we know the importance of having a balanced diet and getting our daily vitamins, some of them have an upper daily limit, which means technically, yes it is possible to overdose on vitamins. Realistically though it’s not going to happen and it's not something you could really do by mistake!
Vitamins are absolutely essential for our health and we should always try to consume the necessary amount per day, the majority of which we can get from our diet. However, despite the importance of vitamins and the natural inclusion of the majority of them in our diets, in recent times there has been an increase in foods and drinks that contain additional or added vitamins and minerals. These can be really useful if you aren’t getting enough in your regular diet, however it's sparked a few concerns for people who think they might be now consuming too many vitamins.
Fat Soluble vs Water Soluble Vitamins
Vitamins are divided into two different types: fat soluble vitamins and water soluble vitamins.
Fat Soluble Vitamins
Fat soluble vitamins are more easily stored in the body when compared to water soluble vitamins and they are able to accumulate and build up quicker. This means they are more likely to lead to toxicity if there is too much of a build-up.
There are four different types of fat soluble vitamins including: vitamin A, vitamin D, vitamin E and vitamin K. Although it is rare, it’s possible to experience side effects from consuming too much vitamin A, D or E. Excluding vitamin K, which has a low potential for toxicity, fat soluble vitamins have set upper limits due to their potential harm when taken in large doses, leading to unpleasant symptoms. Too much vitamin A could cause nausea for example, whilst too much vitamin D can have similar effects, with stomach cramps and poor appetite also being factors.
Water Soluble Vitamins
Whilst there is a small possibility of overdosing on fat soluble vitamins, it’s really uncommon to over consume water soluble vitamins, as these are readily excreted from our bodies when we go to the toilet and therefore aren’t as easily stored in the body.
Water soluble vitamins consist of vitamin C plus eight different types of vitamin B (B1, B2, B3, B5, B6, B7, B9 and B12). Despite the rarity, it is possible to experience side effects if taking certain water soluble vitamins in extremely high doses. Vitamin C, B3, B6 and B9 all have set upper limits that can lead to issues if exceeded.
As mentioned, it’s highly unlikely you will overconsume water soluble vitamins, especially if you are getting the nutrients from natural food sources and any potential issues would come from over supplementation.
What are the Risks of Taking Too Much of Key Vitamins?
Of course, overconsuming different vitamins can have different potential side effects. So, let’s take a look at some of the most common nutrients, and some of the potential risks of overconsuming them
- Vitamin C is one of the most common nutrients, and it is easy to get lots of it from regular diets as it is found in a range of fruit and vegetables. Adults typically need around 40mg of vitamin C a day, and it is unlikely you will experience side effects unless you consume over 1000mg. Taking more than this amount can lead to stomach issues, however these issues should be temporary providing you stop overconsuming the vitamin.
- Vitamin D3 is formed in your skin when it is exposed to sunlight. You can’t overdose on vitamin D3 that is produced in your skin, but if you are taking excessive vitamin D supplements as well as being highly exposed to sunlight, then it is possible to experience side effects such as high blood pressure, nausea and loss of appetite.
- Zinc helps to make new cells and helps process carbohydrates, fats and proteins. It is recommended by the NHS that men consume 9.5mg of zinc a day, and women consume 7mg a day. Taking too much zinc can lead to anaemia and weakened bones, so it’s important to monitor your intake when eating zinc rich foods such as meat, shellfish and cheese.
- Magnesium is a mineral that helps breakdown our food into energy. It is found in spinach, wholemeal bread and nuts and it is recommended that men get 300mg a day and women get 270mg. However, consuming more than 400mg can cause diarrhoea, so you should avoid getting more magnesium than the upper limit.
Remember, although it IS possible to overdose on vitamins, it’s very rare and unlikely that you will experience any issues from over consuming vitamins from regular food, or from adding supplements into your diet. They are completely safe and the upper limits for overconsumption would be difficult to reach even if you tried. Read the labels, look at the RI (recommended intake) and you’ll be fine.