Best vitamin D supplements: reviewed by nutrition experts

Shefalee LothPrincipal researcher & writer

Public health nutritionist with 20+ years at Which? and the NHS delivering evidence-based food and nutrition insights.

Our independent review of vitamin D supplements reveals the products you can trust to give you the best value and quality.

Our nutrition experts have analysed the contents of 30 popular vitamin D supplements, including a mix of tablets, capsules, sprays, drops and gummies. 

We’ve uncovered the most readily absorbed options that will give you the optimal dose with the fewest unwanted extras. We also independently lab test our recommended products so you can be sure they live up to the label. 

How our tests find you the best supplements

We assess how easily absorbed the vitamin D is and whether it’s in a form that aids absorption

We rate the dose level and deduct points for doses that are too low to be effective or excessively high

Based on the latest research and insights, we rate the amount and type of bulkers, fillers and additives in each supplement. The fewer unnecessary extras included, the better

High-scoring products we plan to recommend are tested in an independent testing facility to ensure they contain what they’re claimed to

The best vitamin D supplements 

Only logged-in Which? members can view our full vitamin D supplement test results, including the four top-rated products that scored more than 90%.

Join Which? to get instant access to our test results and Best Buy recommendations below as well as revealing our Great Value picks.

Date tested: September 2025. Page last checked: October 2025. We are not able to show every retailer, and cheaper prices may be available.

The vitamin D supplements we assessed

A selection of popular vitamin D supplements included in our assessment are listed in alphabetical order below.

Only logged-in Which? members can view the best vitamin D supplements and see our full reviews and results.

Join Which? to get instant access to our test results and Best Buy recommendations below.

BetterYou Vitamin D3 1000IU Daily Oral Spray

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Available fromBetterYou (£5.99 for 100 doses), Boots (£8.20 for 100 doses), Holland & Barrett (£7.95 for 100 doses)

Bioglan Vitamin D3 1000IU Vitagummies

Available fromAmazon (£10.99 for 60), Holland & Barrett (£11.75 for 60)

Boots High Strength Vitamin D Tablets

Available fromBoots (£7.80 for 180)

Habi Hey Sunshine Vitamin D Gummies

Available fromBoots (£10 for 60)

Healthspan Super Strength Vitamin D3 Tablets

Available fromHealthspan (£13.99 for 240), Amazon (£14.99 for 240)

Holland & Barrett Vitamin D Effervescent Tablets 1000IU

Available fromHolland & Barrett (£4.49 for 20)

MyVitamins Vitamin D3 Softgels

Available fromMyVitamins (£14.99 for 180), AllBeauty (£5.99 for 60)

Nutravita Vitamin D3 Drops

Available fromNutravita (£15.99 for 2,000 drops), Superdrug (£17.99 for 2,000 drops)

Cost per daily dose 2p (based on the shelf life of two years)

Health? or Hype?

Make the right choice with recommendations you can trust, backed by expert testing.

Explore health recommendations

Solgar Vitamin D3 1000IU Tablets

Available fromSolgar (£17 for 180), Holland & Barrett (£17 for 180)

Superdrug Chewable Vegetarian Strawberry Vitamin D 25mcg

Available fromSuperdrug (£5.49 for 30)

Read more about the supplements you do and don’t need

Viridian Vitamin D3 1000IU Capsules

Available fromViridian (£17.75 for 90), Revital (£17.75 for 90)

Vitabiotics Ultra Vitamin D 1000IU Tablets

Available fromAmazon (£6.15 for 96), Vitabiotics (£6.15 for 96)

Zipvit Vitamin D3 1000IU Tablets

Available fromAmazon (£7.99 for 365),  Zipvit (£7.99 for 240)

More vitamin D reviews

Here are the rest of the vitamin D supplements we tested, listed in alphabetical order.

Only logged-in Which? members can view our full vitamin D supplement test results. Join Which? to get instant access today.

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How we assess vitamin D supplements

We’ve selected a range of popular vitamin D supplements, including sprays, gummies and tablets from big brands and own brands, to uncover the best options.

We’ve focused on products containing 25 micrograms of vitamin D, which is the most popular dose level on the high street. It’s often labelled ‘high strength’ as it’s just over double the recommended amount people are suggested to take to prevent deficiency, but well below the upper safety limit of 100 micrograms for daily use. 

Our review assesses three key factors:

• Bioavailability How easily the vitamin D is absorbed. Some formulations are more readily absorbed by the body than others, and this may impact how much benefit you get from them. 
• Dose Our experts checked whether the supplement contained the appropriate level of vitamin D and if it was enough to prevent deficiency, or if it was higher than is considered safe when taken regularly.
• Additives We assessed what else is in each supplement and whether it’s necessary. The best products contain enough of what you want, and as few unnecessary extras as possible.

To qualify as a Best Buy, a vitamin D supplement had to meet minimum score thresholds for all three key assessments, score highly overall and pass an independent lab check to ensure the vitamin D levels matched what’s on the label. Products that are also significantly cheaper than the average cost are also labelled as Great Value buys.

What makes a good vitamin D supplement?

Most vitamin D supplements contain vitamin D3. This is the most bioavailable, or easily absorbed, form (vs vitamin D2). But some products include oil to improve absorption (vitamin D is fat-soluble), and others don’t. With oil-based supplements, you don’t need to worry about taking them with food to get optimal results, as the fat in them will help absorption, which makes them more convenient. 

Some formats have specific benefits, too. With spray formulations the vitamin D is absorbed directly into your bloodstream from soft tissues in your mouth, bypassing the digestive system. This may be more suitable for people with gastrointestinal conditions that affect absorption such as coeliac disease, Crohn’s disease and IBS.

Together Health supplement that failed our tests

In our analysis of vitamin D supplements Together Health’s vitamin D3 was one of our top-scorers based on bioavailability, dose and additives. Like our other top-scorers and potential Best Buys we sent it for testing. 

However two separate samples failed independent laboratory testing; both contained significantly lower levels of vitamin D than stated on the label which were outside of the permitted tolerance range.  The analysis, conducted by an independent laboratory used an ISO-accredited method suitable for food supplements. 

Together Health strongly disputed these findings, arguing that the chosen testing method is not validated for their specific product matrix. The lab reported that it has found no issues applying this methodology to similar supplements in the past. We asked Together Health to share the testing methodology it uses to validate its samples, but they did not. 

Because of this we are unable to recommend this product.

Why you can trust us: at Which? we’re free from manufacturer and retailer influence. Find out more about our impartiality and how your support helps us to stay editorially independent

What does vitamin D do?

Vitamin D is an essential nutrient with numerous critical roles in the body. Its key function, which underpins several approved UK health claims, is to maintain normal bone and muscle health by absorbing calcium and phosphorus.

Vitamin D also plays an important role in keeping your immune system functioning properly.

Which foods have vitamin D in? 

Foods that contain vitamin D include:

• oily fish such as salmon, sardines, herring and mackerel
• red meat
• liver
• egg yolks
• some mushrooms
• fortified foods including breakfast cereals and fat spreads
• infant formula

While including these in your diet can be a good idea, foodeeds. Hence why taking a vitamin D supplement can be particularly helpful during the autumn and winter months, or all year around if you’re more at risk of developing vitamin D deficiency

Who needs extra vitamin D?

Vitamin D deficiency is the most common nutrient deficiency in the UK, in part due to lack of sunshine in the winter months. This is why the NHS recommends everyone over the age of one takes vitamin D supplements between October and March.

Some people are at higher risk of vitamin D deficiency. If you’re in one of these groups, the NHS recommends that you take a vitamin D supplement all year around.

• People with darker skin tones – melanin reduces the skin’s ability to make vitamin D, and people with dark skin have more melanin.
• People who cover their skin – people who cover up when outside are unable to make enough vitamin D, as their skin isn’t exposed to sunlight.
• People who are indoors a lot – people who are frail, housebound or live in a care home may not get enough exposure to sunlight.

What are the symptoms of vitamin D deficiency?

Low levels of vitamin D may not always cause symptoms. However, according to the NHS, some people can experience:

• tiredness
• aches and pains

Severe lack of vitamin D can cause a deficiency. This may lead to:

• bone pain in adults caused by a condition called osteomalacia
• bone weakness caused by osteoporosis
• rickets in children

It’s not easy to spot vitamin D deficiency. Your doctor can carry out a blood test to check your levels.

How much vitamin D should you take?

NHS guidance recommends that between October and March, everyone above the age of one takes a daily supplement containing 10mcg (micrograms) of vitamin D. This includes pregnant and breastfeeding women – to learn more and see what else you should do if you find out you’re pregnant in 2026, see our guide. 

Breastfed babies should also have 8.5-10mcg a day. Babies on formula milk don’t need an additional supplement, as formula already contains vitamin D. You can find out more in our guide to vitamin D supplements for babies and children.

However, many widely available supplements contain higher doses than this. This isn’t necessarily a bad thing. Lots of people in the UK are likely to be deficient in vitamin D, and taking a supplement containing 10-50mcg a day is generally considered to be safe.

Can you take too much vitamin D?

The NHS advises the following upper safety limits for vitamin D:

• Adults – max 100mcg (4,000IU) a day
• Children aged 10 and under – max 50mcg (2,000IU) a day
• Babies under one – max 25mcg (1,000IU) a day.

Doses can be a bit confusing, as they may be stated in micrograms (written as mcg or μg) or international units (IU). We’ve given both above. 25mcg is equivalent to 1,000IU and is the most common dosage – it should be plenty for most people.

Don’t be tempted by super high doses, and be aware that vitamin D is frequently added to other supplements, as well as some food and drink (especially cereals, smoothies and health drinks), so keep an eye on your overall intake.

If you are extremely deficient in vitamin D your GP may prescribe a higher weekly dose above these limits for a short time period. But don’t go it alone. Taking too much vitamin D over a long period can cause calcium to build up in the body, which can actually weaken bones and damage your heart and kidneys. This is known as hypercalcaemia. 

Do vitamin D supplements work?

Yes. Experts recommend that everyone in the UK takes a vitamin D supplement during the autumn and winter months. This is because, due to low UV levels in the UK in winter, our bodies can’t produce enough of it naturally (from daylight) between October and March, and you can’t get enough from food

Best multivitamin and mineral supplements – see our independent expert reviews for the best options to buy

What’s the best type of Vitamin D to take? 

There are two forms of vitamin D in supplements: D2 (ergocalciferol) and D3 (cholecalciferol). Both are absorbed in the small intestine, although some studies have shown that vitamin D3 supplements are better at raising vitamin D levels than D2 supplements.

Some supplements contain both vitamin D and K. This is because both are needed for calcium metabolism. However, the current evidence doesn’t suggest you need to take supplements that combine the two, especially as it’s easy to get enough vitamin K from your diet (think leafy greens).

Vitamin D supplements come in plenty of different formats – from sprays and gummies to tablets and liquid drops. Sprays, drops and gummies are handy if you prefer alternatives to swallowing pills or have digestive issues that impact absorption. Supplements with added oils mean you don’t need to worry about taking them with food, as the fat in them will help absorption. 

When is the best time to take Vitamin D?

There is no specific time of day that’s been shown to be the best time to take Vitamin D. The most important thing is consistency, so it’s best to choose the time of day that will be most convenient and practical for you. 

Vitamin D is a fat-soluble vitamin, so if you’re taking it in a format that doesn’t include any oil, such as a tablet, then it’s best to take it with fat-containing foods for optimum absorption.  

Who shouldn’t take Vitamin D? 

If you have any pre-existing health conditions or take regular medication, you should check with a healthcare professional such as a doctor or pharmacist before starting to take any supplements, including Vitamin D.

Some medications, including diuretics, high blood pressure and anti-seizure medications, can interact with Vitamin D, affecting their absorption and/or effectiveness. 

Babies fed more than 500ml of infant formula a day shouldn’t be given Vitamin D supplements because formula already contains it.  

Our supplement experts

Our Vitamin D assessment was conducted by Which? nutritionist Shefalee Loth and Sophie Medlin, consultant dietitian.

Shefalee Loth, Which? principal researcher and nutritionist

Shefalee is a public health nutritionist with 20 years’ experience, and has worked for the NHS, The London School of Hygiene & Tropical Medicine and World Cancer Research Fund.

At Which?, Shefalee is a principal researcher, researching and writing food and nutrition content for our magazine and website. She is also a media spokesperson and the research lead for our health and wellbeing reviews. She is a trustee at Sustain, the food and farming alliance.

Shefalee focuses on cutting through the hype to explain what you need to know about nutrition and healthy <a href="https://health.kporia.com/more-americans-are-eating-fruit/” title=”More Americans Are Eating Fruit”>eating. From ‘How bad is ultra-processed food?’ to the ‘Top gut health myths you need to know about’ and ‘What really works to cut cholesterol’, she gives no-nonsense advice to help you make healthier choices and save money.

Sophie Medlin, consultant dietitian and founder of CityDietitians

Sophie Medlin is a well-recognised consultant dietitian with nearly 20 years’ experience working across the NHS and academia and within her own private practice at CityDietitians. 

Sophie is chair of the British Dietetic Association for London.

With her in-depth knowledge of nutrition – both theoretical and applied – Sophie has helped to formulate supplements, giving her insight into the strengths and weaknesses of products and the manufacturing process.

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