How much vitamin D supplement do you need to take?

Everyone should take a vitamin D supplement for bone and muscle health. The amount you need depends on your age, skin tone, situation and the season.
Updated in November 2023
People on the island of Ireland don’t get enough vitamin D from their diet or from the effect of sunlight on their skin. So, people are recommended to take Vitamin D supplements. The amount you need depends on your age, your skin tone, how much time you spend outdoors and the time of the year.
Here is how much and when different people need to take a vitamin D supplement. The symbol “µg” stands for “micrograms”.
Babies under 1 year: 5µg
Including:
- Babies who are exclusively breastfed
- Babies who drink less than 300ml of infant formula per day
Exception: Infant formula has added vitamin D so if your baby drinks more than 300 ml of formula, they do not need a vitamin D supplement.
Children aged 1-4: 5µg
- During the winter months (Halloween to St Patrick’s day)
Children aged 5-12: 10µg
- During the winter months (Halloween to St Patrick’s day)
- All year round for those with reduced sun exposure or darker skin tone.
Teenagers and adults: 15µg
- During the winter months (Halloween to St Patrick’s day)
- All year round for those with reduced sun exposure or darker skin tone.
- Every day during pregnancy
Adults over 65 years: 15µg
- All year round
What is Vitamin D?
Vitamin D, also known as the ‘sunshine vitamin’, is one of the few vitamins our bodies can produce itself. During the summer, our bodies make vitamin D through direct sunlight on our skin. However, in the winter months sunlight is not strong enough to make Vitamin D and so we must get the sunshine vitamin from elsewhere.
Can you get vitamin D from food?
Small amounts of vitamin D can be found naturally in some foods, including fresh and tinned oily fish such as mackerel, salmon, trout, kippers and sardines.
Many fortified foods now include vitamin D, such as margarine and low-fat spreads. Other foods are fortified with Vitamin D including some breakfast cereals, milk, yogurts, plant based drinks and some powdered milks. The amount of vitamin D in these products varies, so it’s important to check the label. Often the amount of Vitamin D address is quite small, so it is important that you still take the recommended supplement.
What does vitamin D do?
- Vitamin D helps to keep our bones and muscles healthy. There is also evidence that it supports our immune system.
- A lack of vitamin D can increase the risk of osteoporosis over time, causing our bones to weaken and become brittle and increasing the risk of fractures and breakages.
- Vitamin D deficiency has also been linked to various health conditions such as cardiovascular disease, diabetes, some inflammatory disorders, certain cancers, and higher mortality.
Is there such thing as too much vitamin D?
Yes, it is possible to take too much vitamin D. This can happen if you take more than the recommended amount of vitamin D in a supplement. Taking too much over a long period of time can weaken the bones, kidney, and heart due to a build-up of calcium in the body. That is why you should not take more than the recommended amount, unless your GP advises you to do so.
Where can I buy a vitamin D supplement?
You can buy Vitamin D supplements without a prescription in your local pharmacy.
There is a wide range of Vitamin D and multivitamins available on the market, so it is important to check with your pharmacist or healthcare professional to ensure that you are taking the right one.