food supplements, dietary supplements, vitamins, minerals

If you walk around your local supermarket, pharmacy or health food shop you will see a huge selection of vitamins, minerals and other nutritional supplements in a bewildering range of doses, and combinations.

But do you really need these supplements or are they just a waste of money? Mixed messages from the media, family and friends can make things even more confusing. This Food Fact Sheet will help you decide.

What are supplements?

As the name implies, supplements (dietary / nutritional) are any product that aims to ‘supplement’ the diet with nutrients that could potentially be missing. Popular supplements include vitamins D, C and B12, minerals like iron and calcium, herbs like echinacea and products like fish oils and probiotics. Dietary supplements are available in a variety of forms, including tablets, capsules, gummies, spray and powders.

Who needs supplements?

People take supplements for a wide variety of reasons. The most common of these is wanting to maintain or improve their health. However, it may be better to focus on enhancing dietary quality before considering supplements. You can do this by eating:

  • Plenty of fruits and vegetables – aiming for a variety and at least 5-a-day
  • Some starchy foods such as bread, potatoes, rice and pasta with each meal. Wholegrain options are healthier choices
  • Some milk and dairy foods (or suitable dairy free alternatives which are fortified with calcium, such as fortified soya, coconut or oat-based products). Adults need two to three servings per day to reach the recommended amount of calcium
  • Some beans, pulses, fish, eggs, meat or other foods rich in protein – two portions per day. Try to replace meat with pulses once or twice a week
  • Limiting foods which are high in salt, sugar and fat

It is important to note that there is no supplement that provides the same nutritional benefits of a healthy balanced diet.

There are certain groups of people who may benefit from taking supplements.


Which supplement?


Vitamin D

All babies under one year of age



8.5-10 micrograms of Vitamin D in vitamin drops per day

Babies who are having more than 500ml of infant formula a day should not be given vitamin supplements

To prevent vitamin D deficiency

Adults and children aged one year and older


10 micrograms of Vitamin D per day during autumn and winter months

Some groups, including those who are not able to go outside often or who cover their skin when outside, and people with darker skin are advised to consider taking vitamin D all year round

To prevent vitamin D deficiency


Folic acid

Women who are pregnant, trying to conceive or could become pregnant  






400 micrograms of folic acid daily from pre-conception until 12 weeks of pregnancy.

A higher daily dose of folic acid (5mg) is recommended for women at a high risk of conceiving a child with neural tube defect, including those who have previously had an infant with neural tube defect or women who have diabetes of sickle-cell disease.

To reduce the risk of neural tube defects in the unborn baby



People who suffer from certain medical conditions for example iron deficiency anaemia, or if you have had stomach surgery

As recommended by your doctor

To prevent or correct a deficiency

People following a vegan diet  

10 micrograms of vitamin B12 daily

Up to 150 micrograms of iodine daily

Do not exceed this dose unless advised by your healthcare professional as excess iodine can be harmful

To prevent deficiency of these nutrients


Speak to your doctor, midwife or health visitor to see if you qualify for Healthy Start vitamins for women which contain folic acid, vitamin C and vitamin D or Healthy Start children’s vitamin drops which contain vitamins A, C & D.

Have a look at our Vegetarian, Vegan and Plant-Based Diet Food Fact Sheet as well as our factsheets for individual nutrients including Vitamin D, Iodine and Folic acid for more information.

If you think you are not having enough of one or more nutrients and are thinking about taking a supplement, always consult your doctor, or ask to see a dietitian.

Choosing a supplement

  • Always buy supplements from a reputable source - for example, your local chemist, pharmacy or supermarket, and not from an unknown company on the internet
  • Check the label – it should tell you the amount in each dose and should have an expiry date
  • Make sure you really need the supplement - ask your doctor, dietitian, pharmacist or chemist

What are the risks of taking a supplement?

Quality - Internet products may not meet UK standards and may not have gone through the same checks as products from a more reliable source. There could be less of the active ingredient than claimed, or the product could contain ingredients harmful to your health. If you want to buy supplements via the internet choose a recognised high street retailer that also trades online.

Quantity - Taking too much of a vitamin or mineral can be dangerous. You can make sure you don’t take too much of any vitamin by only ever taking the recommended dose on the label (unless advised by your doctor). Also check that the supplement does not provide more than the daily recommended.

If you take more than one supplement, make sure that you are not doubling up on any nutrients. For example, if you take a multivitamin tablet which includes vitamin D, don’t take an additional vitamin D supplement unless advised to by a health professional.

Other risks

  • Wasting your money! Supplements can be expensive and a lot of them have no proven benefits at all. They may claim to delay ageing, boost your metabolism or make you slimmer but in fact there is little or no evidence to back up many of these claims
  • Supplements may have interactions with some medication and some are unsafe if you suffer from certain medical conditions. This is why it is important to talk to your doctor before taking any supplements
  • If you are pregnant you should not take fish liver oil as it contains vitamin A, which can be harmful to babies in large amounts
  • If you have cardiovascular disease, avoid vitamin E supplements as these can increase the risk of further heart attacks
  • Effervescent (fizzy) vitamin supplements contain approximately a gram of salt per tablet. So you might want to consider changing to a non-effervescent alternative, especially if you have been advised to limit your salt intake
  • The term ‘natural’ doesn’t always mean safe. Some natural botanical products can damage the liver. The safety of a supplement depends on a number of factors, including how it is prepared, how it works in the body and how much of it you consume

Top tips

  • There is no nutritional supplement that can have the same benefits as a healthy balanced diet
  • We should all consider a Vitamin D supplement, especially during winter months
  • All women who are planning pregnancy should take a folic acid supplement, and continue until 12 weeks gestation
  • Vegan diets may need supplementation with Vitamin B12 and iodine
  • Be cautious where you are buying your supplements from. Unlicensed or unregulated websites may not be safe


Practice-based Evidence in Nutrition (2018) Dietary Supplements Knowledge Pathway. [online] available by subscription from

National Institute of health (2020) Dietary Supplements: What You Need to Know. Available from:

NHS (2021)  Vitamins for children. Available from:

Jenkins, D.A, Spence, J.D, Gionvannucci, M.D et al (2018) Supplemental Vitamins and Minerals for CVD Prevention and Treatment, [online] Available from:

NICE (2015) Improving maternal and child nutrition. Available from:

NHS (2020) Vitamin D. Available from: