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How much vitamin D per day do I need?

Vitamin D is known as the sunshine vitamin because it’s produced by the action of the sun’s rays on our skin. But long winters and poor British summers mean many of us may be deficient. As we’re spending more time in our homes, a daily dose of Vitamin D has never been more important to help you and your family stay well.

How much vitamin D should I take?

Department of Health recommendation is around 10 micrograms a day. It is recommended to take supplement containing 10 micrograms of vitamin D during autumn and winter, and throughout the year for those who are not often outdoors. Taking more than 100 micrograms (4,000 IU) a day could be harmful to your health. This applies to adults, children, the elderly, and those who are pregnant or breastfeeding.1

What is vitamin D?


Vitamin D is actually a hormone produced by the body. It was named by mistake after it was noticed that rickets could be treated with cod liver oil, which is rich in the vitamin.

While vitamin D is found in certain foods, such as oily fish, milk and eggs, around 90 per cent of our supply comes from the sun – our skin makes vitamin D when it is exposed to ultraviolet B (UVB) rays.

What are the benefits of vitamin D?

There are many benefits of vitamin D such as2:
  1. Supports the maintenance of normal bones
  2. Supports the maintenance of normal muscle function
  3. Supports the normal function of the immune system
  4. Contributes to the maintenance of normal teeth

Vitamin D contributes to normal absorption/utilisation of calcium and phosphorus, and contributes to normal blood calcium levels.

Why aren’t we getting enough vitamin D?

Around 50 to 60 per cent of the British population is insufficient in vitamin D5. Increasing sun safety awareness – more of us are using sun block – long winters and poor summer sunshine all mean we’re not producing enough of the vitamin.

From October to March in the UK, sunlight doesn’t reach the earth at the correct angle, so, in turn, not enough UVB rays reach us in order to produce vitamin D.

Some groups are also more vulnerable. The elderly or housebound, dark skinned, pregnant or breast-feeding women, those who cover their skin and those with a poor diet could be deficient in vitamin D.

How to get more vitamin D


Getting some summer sunshine is the best way to increase your vitamin D, but there’s no need to sunbathe. Spending around 15 minutes outside every day should be sufficient.

You can also add vitamin D-containing foods to your diet:

  • oily fish like salmon or mackerel
  • eggs
  • liver, meat
  • fortified foods such as spreads, and cereals
  • baby formula is fortified with vitamin D by law

You can try taking a vitamin D supplement too, either as a tablet or spray, which delivers the vitamin under your tongue and straight into the blood stream. Pregnant and breastfeeding women can get vitamin D supplements from their GP.

Differences between vitamin D2 and D3

Vitamin D3 is the same form that your body produces when exposed to UV light, whereas vitamin D2 is what plants produce when they are exposed. Find out more about

Can you take too much vitamin D?

Yes, you can and that is why there is a recommended allowance that you should not exceed. Too many supplements over a prolonged period can lead to hypercalcemia, which is the buildup of too much calcium in the body. Hypercalcemia can weaken bones and cause damage to the kidneys and heart.

It is impossible to overdose on vitamin D by being in the sun too much, however, it is always recommended to take precautions when exposing your skin to UV light.6

Side effects from too much vitamin D

The following side effects could be a sign that you have had too much vitamin D7:
  1. Elevated blood levels
  2. Elevated blood calcium levels
  3. Feeling nauseous and vomiting
  4. Loss in appetite
  5. Pain in the stomach
  6. Constipation or diarrhea
  7. Bone loss (due to reduced vitamin K2 activity)
  8. Kidney injury

Summary of vitamin D

You should hopefully be clearer about how much vitamin D you should aim to get daily and the associated health benefits.

Before taking vitamin D supplements, and especially if you have a pre-existing health condition or currently take medication, it’s always a good idea to have a chat with your GP.

We have a range of vitamin D supplements that come in various forms including tablets, capsules, liquids, gummies, sprays and more. We also have a range of vegetarian and vegan options too. Shop Vitamin D 
Andrea Dobronszki

Author: Andrea Dobronszki, Regulatory Affairs

  • Joined Holland & Barrett: August 2020
  • Qualifications: Master’s Degree in Food Science and Technology Engineering, Bachelor’s degree in Dietetics

Andrea started her career as a clinical dietitian and lecturer at a university hospital, managing the dietetic treatment of patients with various diseases, and giving lectures in nutrition for medical students. Later she worked as a Product Developer at a sport nutrition company where she developed food supplements and fortified foods, and ensured that the products complied with the relevant regulations. Andrea joined Holland & Barrett as a Senior Regulatory Affairs Associate and specialises in food supplements, food regulations, nutrition and dietetics.

View Andrea’s LinkedIn profile

Last updated: 31 December 2020

Vitamin D