If you live above 40 degrees latitude, you will not get enough vitamin D all year round. Ensure you get sufficient vitamin D from spring to early autumn by eating fish three times a week and six eggs a week. Also, expose your arms and face for at least 30 minutes a day and take a vitamin D  supplement that provides 15mcg of vitamin D. During the winter, however, this may not be enough. If you feel low in the winter months, supplement an extra 25mcg (or 1,000iu) vitamin D3. If you are vegetarian, take vitamin D2, although the D3 is the right choice. So we will help you to find the best vitamin D supplements in the UK.

After the Second World War, when rickets caused by vitamin D deficiency was a major health issue in the UK, all children in Britain were given cod liver oil, providing not only vitamin D but also essential omega-3 fats and vitamin A. After supplementation was ceased, and combined with the decline in eating fatty fish, vitamin D levels of people in the UK decreased and have done so ever since, with most people eating fewer than one serving of oily a week. The average woman in Britain achieves the only 2.7mcg, while the average man achieves 3.1mcg, compared to the hopelessly low RDA of 5mcg.

Many experts believe that we need as much as 30mcg a day in total. Given that sunlight makes vitamin D, and a lack of sunlight is linked to feeling low and cause other health problem. That is why getting enough vitamin D is important for optimal health. You can achieve this by taking the best quality vitamin D supplement,


Our Top Picks

Vitamin D3 (Cholecalciferol)

  • Nutravita: 4000 IU, 400 soft gel capsules and 13 months supply.
  • Nu U Nutrition: 4000 IU, 365 soft get capsules for full-year supply.
  • Vita Premium: 4000 IU, 365 soft get capsules for 12 months.
  • Incite Nutrition: 4000 IU, 400 easy to swallow tiny tablets and 12+ months, suitable for vegetarians
  • WeightWorld: 4000 IU, 365 easy to swallow tablets and for 12 months, suitable for vegetarians.

Vitamin D2 (Ergocalciferol)



best vitamin d supplements uk

Best Vitamin D Supplements in the UK 2020 Quality Ranking

vitamin D3







Recommended  Vitamin D2 Supplement

Which Type of  Vitamin D Supplement is Best? 

The term vitamin D is kind of a misnomer because you will not find anything that is simply labelled vitamin D. Your choices will be either vitamin D2 or vitamin D3. When a supplement mentions vitamin D, the implied selection is vitamin D2. So the name can be confusing because many times, we go into the pharmacy to buy and we are surprised that there is a D2 and a D3.

Vitamin D2 comes from plant sources, such as wild mushrooms, as well as fortified foods, such as milk or cereal. Its strength is typically measured in international units, which is abbreviated as “IU” on labelling. The 50,000 IU capsules are prescription only, while lower strengths are available to buy online or over-the-counter.

Vitamin D3 mainly comes from animal sources such as fish oil, fatty fish, liver, and egg yolks. When our skin is exposed to sunlight, it produces vitamin D3. This is the reason it is sometimes called the sunshine vitamin. The strength of this is also measured in international units.

So here’s what you need to know about what exactly is the difference between vitamin D2 and vitamin D3, and is one better to take over the other?

What is Vitamin D2 (Ergocalciferol) Used for

We don’t make our own vitamin D2—unlike vitamin D3, which is active in the body. Vitamin D2 can only be found in supplements as well as certain plants that have been exposed to UVB rays, like mushrooms. When we consume it, the vitamin will be stored in dietary fats, absorbed in the small intestine, then it will be activated—first in the liver, followed by the kidneys. When activated, the body will deliver it to the target tissues. It will promote healthy immune function, support strong bones, and even support our reproductive function.

We should not overdose too much vitamin D2, the upper limit for adults is “4,000 IUs per day. Overdose can cause the body to absorb too much calcium, which will lead to calcification (calcium buildup) in the organs. Too much of this essential vitamin can also harden children’s bones prematurely.

What is Vitamin D3 (Cholecalciferol) Used for

When we associate vitamin D with sunshine, we are actually referencing vitamin D3. When our skin is exposed to UVB rays, 7-dehydrocholesterol is converted to pre-vitamin D3 in our body, which eventually turns into vitamin D3. Because we get it from the sun and this is naturally occurring, we can’t overdose on vitamin D3. If we are absorbing too much, our body will adjust and produce less.

That being said, vitamin D3 can also be found in animal sources from protein like chicken, eggs, oily fish like salmon and sardines as well as from supplements. Vitamin D3 is more active in the body than vitamin D2 and is often converted to calciferol, the type of vitamin D that raises our blood levels.

So how much vitamin D3 is too much, unlike vitamin D2, higher doses of vitamin D3 will boost your immune system function, support bone health and support reproductive function. The maximum limit is 10,000 IU per day, even though the dosage is so high, side effects are rare but for some people, they can experience frequent urination, confusion, muscle weakness, bone pain, extreme thirst, weight loss or decreased appetite, constipation, nausea, vomiting and toxic levels in the blood.

Which One is Better to Take as a Supplement? D3 vs D2

The difference between ergocalciferol all vitamin D2 and cholecalciferol vitamin D3, both of these forms of the vitamin are found in supplements. The ergocalciferol, all vitamin D2 is the preferred form of the vitamin to be used in the medical industry and therefore if you take a prescription vitamin D supplement, you will be taking ergocalciferol. The type of vitamin D used in supplements varies.  You need to check the labels.

We would recommend that if you are looking at a vitamin D supplement, take the cholecalciferol form of the vitamin that is the vitamin D3 form.  Because it is more biologically active and therefore the recommendations to take vitamin D, you will not have to adjust them if you take the vitamin D3.

If you take vitamin D2 ergocalciferol and you follow the recommendations to take vitamin D, you will need to increase your dose. Because the amount of vitamin D2 you take will not raise your plasma levels of vitamin D to the same level as if you took vitamin D3 form.

Most vitamin D supplements contain vitamin D2 when we buy it from the pharmacy. But vitamin D3 tablets are considered better choice because they are generally of best quality and research suggests vitamin D3 supplements increase vitamin D2 status in the body. Vitamin D3 has been proven to be better absorbed and utilised by the body than vitamin D2.

However, because most vitamin D3 supplements come from animal sources, and there is little research to support whether vitamin D3 from lichen (a plant-based alternative) is actually usable in the body, vegans and vegetarians might want to take a high-quality vitamin D2 supplement.

However, there are no specific health reasons someone would have to take D2 over D3. You can take them interchangeably, but always buy vitamin D supplement based on its quality and whether or not it is a reputable and trusted brand. Following are the list of the best vitamin  D2 and D3 supplements brand in the UK.

What is Vitamin D3 Deficiency 

Vitamin D3 deficiency is currently the most common vitamin deficiency disease in our latitudes. Until recently, there was little awareness of vitamin D3. Depression, fatigue, and weakness – typical symptoms of deficiency – were simply assumed to be psychological impairments, and patients’ vitamin D3 levels were rarely considered.

Thankfully, this attitude is gradually changing. Even though the health insurance still does not cover vitamin D3 testing, and patients typically have to bring up the possibility of D3 deficiency in consultation, many people now know about the importance of vitamin D3 and are starting to take their health into their own hands.

Vitamin D3 is actually the biologically active form of a hormone. It is required in several metabolic processes and affects 3,000 genes in our body. There are many diseases in which vitamin D3 deficiency is involved. In everything from autism and heart disease to diabetes, rheumatoid arthritis or cancer, many studies have shown that an adequate supply of vitamin D3 alleviates or even prevents many diseases – including many chronic ones.

Vitamin D3 is derived from cholesterol only when the skin is exposed to sunlight. We develop a deficiency if we spend too little time in the sun in the summer months.

Fortunately, vitamin D3 treatment is simple, inexpensive and risk-free. In addition, vitamin D3 storage can be replenished within a few days. High-dose vitamin D3 treatment often leads to an almost miraculously speedy resolution of symptoms.

What are the Causes of Vitamin D3 Deficiency?

When we consider the conditions under which the human organism has evolved over many millennia, we see that we have moved far away from our original way of life. Our ancestors were always on the move, hunting, securing their homes, and gathering plants. Many thousands of years later, they started cultivating their fields or keeping livestock. While performing these activities, they were out in the open air and were typically exposed to sunlight from morning to evening.

Even though they were unable to produce vitamin D3 in the winter due to the lack of sunlight, they had stored enough over the summer to carry them through the long winter.

Today, things look very different, because we spend a large proportion of our time within closed rooms – even in the summer. We usually get far too little sunlight and natural light. But our bodily needs have biologically evolved over a very long time and are still the same as they were thousands of years ago. No wonder, then, that vitamin D3 deficiency is this prevalent in today’s world!

When we do go outside, our vitamin D levels aren’t affected much, because we’ve come to think of the sun as a very dangerous thing over the past few decades. We have lost sight of the healing powers of the sun. When it’s spring, experts regularly remind us to use high SPF-lotions at the slightest sun exposure. However, this prevents vitamin D3 from forming in the skin as sunscreen blocks the UVB radiation that is, in fact, the first catalyst of vitamin D3 production.

However, we only receive this UVB radiation in our latitudes between April and September, when the sun is over 50 degrees above the horizon. And if it is cloudy or if there is heavy air pollution – as is the case in many large cities – far less radiation actually reaches us, even in the summer. So it is quite possible to get a good tan from sunbathing in UVA radiation (which causes no vitamin D3 formation), while still suffering from a lack of vitamin D3.

To put it bluntly: spending a lot of time in the sunlight, without protection, can undoubtedly be harmful. But as with many things, this is about getting the right amount: too much sun is just as harmful as no sun. All in all, we all receive far too little sun exposure, so there is little chance of stimulating vital vitamin D3 formation in our skin. Natural daylight is also important to our health and wellbeing, as it regulates important hormones.

Who in Particular Needs Vitamin D3?

Smokers need more vitamin D3 than non-smokers. In addition, there are a few medications such as anti-epileptic drugs that can disrupt vitamin D3 metabolism. The activation of vitamin D3 may be reduced in people exposed to heavy metals, as is increasingly common today. Barn door vitamin D3 deficiency is often exhibited by dark-skinned people from Africa or the Middle East who live in our latitudes. Because they are genetically adapted to an area where there is a lot more sunshine than here, their skin generally produces less vitamin D3. Almost all of them suffer from severe vitamin D3 deficiency.

If infants are never allowed to sunbathe for a few minutes without sunscreen, they will not have enough vitamin D3. Senior citizens in nursing homes almost all have a marked vitamin D3 deficiency since they hardly get into the sun, and because vitamin D3 synthesis is reduced in old age.  The most common symptoms

The most common symptoms of vitamin D3 deficiency are

  • listlessness, lack of energy, constant exhaustion, low mood
  • disturbed nervous function, sleep disturbances, restlessness, inner restlessness, difficulty concentrating
  • headache, migraine
  • muscular cramps (calf cramps), muscles twitches and tremors (eyelid spasms), muscle weakness
  • osteoporosis and pain due to bone softening and deformation, joint pain
  • coordination impairment, unsteady gait
  • circulatory and perfusion disorders, cold hands and feet

The musculoskeletal function is dependent on adequate calcium intake and supply. With a vitamin D3 deficiency, the calcium supply to the muscles is impaired and the muscle cells that need calcium cannot “start” properly. This is experienced as exhaustion and severe fatigue.

Nerve cells, like muscle cells, are also activated by calcium. Lack of calcium due to vitamin D3 deficiency limits cognitive function. This leads to insomnia, fatigue, concentration problems, restlessness, inner restlessness, and cognitive decline. Of course, calcium intake also needs to be sufficient, but muscle weakness is usually due to vitamin D3 deficiency as opposed to an isolated calcium deficiency.

The diet should also not be too acidic, to prevent excessive renal excretion of calcium. Fruits, vegetables and salads are best suited to meet the calcium requirements; furthermore, they are alkaline-forming foods. Dairy products also contain a lot of calcium, but because they make the body acidic, more calcium is excreted than is consumed. In addition, milk causes osteoporosis and is carcinogenic, as detailed in the book “The China Study”. Dairy products should, therefore, be consumed with great moderation.

Vascular musculature is also affected by vitamin D3 deficiency. There are small circular muscles in all vessel walls that ensure their elasticity. If vitamin D3 deficiency also causes a lack of calcium supply to these tissues, the activity of the circular muscles is reduced. Getting up quickly at night can lead to sudden dizziness, as blood pools in your legs. In cases of severe calcium deficiency, dizziness and circulatory problems also occur during the day.

Frequent headaches result from compensatory mechanisms: if blood pressure is reduced because the vessels are expanding due to calcium deficiency, adrenaline is suddenly released to cause vascular contractions in order to sustain blood pressure. However, this adrenaline also leads to the contraction of vessels in the head, which then manifests as a headache. Even cold hands and feet can be explained by the vascular cramps that arise when adrenaline rushes into the bloodstream.

Because vitamin D3 affects more than 3,000 genes in our body, rarer symptoms may arise. Dr Raimund von Helden’s book “Healthy in seven days – successes with the vitamin D therapy” (which is worth reading, but is available only in german), contains the accounts of a patient with months of constant pains all over the body; a child with anorexia who would vomit whenever they ate; a patient who heard voices; a man with inflammatory bowel disease; a woman with tinnitus; and a girl with asthma. All these symptoms resolved within days to weeks of high-dose vitamin D3 treatment.

Vitamin D3 Benefits

1. Vitamin D3 increases energy and improves mood

Vitamin D3 deficiency is probably the most common cause of tiredness, weakness, fatigue and low moods. For depression and general lack of energy, one of the first measures should generally include an investigation of vitamin D3 levels. With enough vitamin D3 in the body, all the cells in the muscles and brain can actually work properly. It is always amazing how a lack of energy, a lack of motivation, and depressive moods dissolve within a few days of starting high-dose therapy.

2. Vitamin D3 for healthy bones and muscles

Vitamin D3 is extremely important for healthy and strong bones and teeth. It helps to absorb calcium from the diet, increases bone mineralization, and inhibits bone loss. A severe vitamin D3 deficiency can lead to various bone pains, joint aches, and often causes back pains. It can get so severe that the bones begin to soften and deform. Vitamin D3 is also important for strong muscles as it stimulates muscle growth.

3. Vitamin D3 helps with asthma

One should always check vitamin D3 levels in asthma. In English-speaking countries, vitamin D3 is widely known to be a very good treatment for asthma, which is probably due to its anti-inflammatory effect. A friend of mine, who often spent the winter in Asia and was exposed to the sun there, wondered why her asthma continuously improved out there. Since taking vitamin D3, she achieved the same level of symptoms control in Germany as in Asia.

4. Vitamin D3 for a strong immune system

Vitamin D3 is very important for a functioning immune system. People with low vitamin D3 levels usually have to deal with infections in late winter and spring, when levels are at their lowest. Vitamin D3 helps to activate white blood cells during infections. A link between the disease and the lack of vitamin D3 has been found in various autoimmune diseases such as Crohn’s disease or multiple sclerosis.

5. Vitamin D3 helps prevent cancer

Dr Garland, a professor of preventive medicine at the San Diego School of Medicine, announced with colleagues that a global total of 600,000 cases of breast and colon cancer could be prevented by normalizing vitamin D3 levels. This has been proven in 200 human studies and more than 2,500 laboratory studies. In a study done by the vitamin D researcher Dr William Grant, it was shown that about 30% of all cancer deaths could be avoided through ensuring sufficient vitamin D3 intake.

In a large placebo-controlled study on vitamin D3 and cancer, this figure even rose to 60%. This study prompted the Canadian Cancer Society to recommend vitamin D3 as a preventative measure. These are incredibly impressive results that clearly show the importance of vitamin D3.

How to Treat Vitamin D3 Deficiency 

As you’ve seen in the list of symptoms, a sufficiently high level of vitamin D3 supplementation will benefit your overall physical and mental well-being. Therefore, if you suspect that you are deficient, do not hesitate to ask your doctor to carry out a blood test and to determine your vitamin D3 level. You need to be proactive about this because most doctors don’t automatically consider the possibility of D3 deficiency, even if you have depression or muscle twitching or other typical symptoms.

Vitamin D3 in and of itself is not a topic covered in medical school, and pharmaceutical companies are not interested in cheap stuff that isn’t profitable, or in anything that will rapidly restore health in its consumers. So doctors are still terribly under-informed about it. The vitamin D3 level (25-hydroxy-cholecalciferol) is determined through the blood test. The test itself is relatively accurate and costs about 3o Euros.

If a deficiency is confirmed, the test is often, but not always, covered by insurance. In such instances, insurance also covers the cost of therapeutic vitamin D3 supplementation. Should you decide to get your vitamin D3 by yourself, there are many cheap options in the mail order industry and on the internet. In Holland, for instance, I order my high-dose vitamin D3 which is dosed at 50,000 units per tablet. It is at least 5096 cheaper than Dekristol, the only high-dose preparation that is licensed in Germany, and I don’t need a prescription for it.

If you don’t feel like going to the doctor, you can now also buy home test kits from various online providers, with which you take a few drops of blood and send it off. The analysis and assessment are then sent to you by mail within two days.

Since a test almost always confirms the suspicion of a vitamin D3 deficiency, you can – if you don’t want to go to the doctor – skip the test and immediately start taking vitamin D3. Vitamin D3 supplementation is very safe and overdose is unlikely. However, you should get yourself a high-dose vitamin D3 preparation.

What is Your Vitamin D3 Levels?

The normal vitamin D3 range is 50-70 ng/ml. However, a level of 100 ng/ml is completely harmless. For many people, the serum vitamin D3 level lies below the determinable limit of 7 ng/ml. 16-18 ng/ml is the low average level in Germany. So, given that your blood D3 level is likely to lie below 50 ng/ml, taking vitamin D3 will be of great benefit to your health.

A high vitamin D3 level is safe up to 150 ng/ml, and severe poisoning is only diagnosed at levels above 300 ng/ml. If the value is higher, you may experience symptoms of hypercalcemia (high calcium levels, which leads to excessive thirst, confusion, fatigue), but this will quickly renormalize as the vitamin D3 level drops back down.

Daily sunbathing cannot lead to such high levels; instead, this causes levels to settle at about 80 to 90 ng/ml. If your level is approx. 25-30 ng/ml and your doctor tells there’s nothing to worry about, please don’t stop taking your supplements. Although it would put you above the national average, it is still far from the ideal level. Maintaining optimal vitamin D3 levels is one of the best disease prevention measures you can adopt in your life. If you don’t want to get a blood test, ask yourself the following questions: Do I avoid the sun? How often do I go swimming? Do I use sunscreen? Is my skin pale?

If you have minimal sun exposure and have several of the symptoms mentioned above, you are almost certainly deficient in vitamin D3 and can easily start taking supplements. You would have to consume a heroically large quantity of vitamin D3 to reach dangerous levels; as such, supplementation is very unlikely to pose a risk. You can also take these foods to increase vitamin D levels.

Recommended Dose

You can easily calculate your required dose of vitamin D3 yourself. To raise the level by 1 ng/ml in a 70kg adult, you need 10,000 units of vitamin D3. Let’s say you have a level of 10 ng/ml and you want to reach 50 ng/ l. Then you would have to take 40 times 10,000 units, i.e. 400,000 units of Vitamin D3. Thus, your level would be at the minimum recommended vitamin D3 level. If you want to reach 60 ng/ml, you will need to consume 500,000 units. Of course, if you weigh less or more, you’ll need to adjust the dose accordingly.

These are, of course, approximate values. This formula gives good results with a margin of error of approx. 10%. In his book, Dr Helden recommends saturating your body with vitamin D3 levels within just a few days. In fact, only 4-5% of people experience side effects when they consume such high doses of vitamin D3 within just three or five days. These effects aren’t terrible: they typically include head pressure, fatigue and indigestion, which pass after a few hours or days.

However, these side effects can be further minimized by slightly spacing out the initial treatment doses, e.g. extending a one-week high-dose course to two weeks of lower-dose treatment. For the initial dosage, we recommend that you take the required units within ten days to two weeks. To take a total of 500,000 units, for instance, you could consume 50,000 units every day. Don’t be surprised if you feel better right away and find that your mood and general well-being have improved!

How to Reduce the Toxic Effects of Vitamin D

There are incredible benefits of taking higher levels of vitamin D. So how to get the benefits from taking more vitamin D without the toxic side effects? The first thing that you need to know is that the only toxic effect of taking high levels of vitamin D has to do with calcium, too much calcium in the blood. It doesn’t have to do with the D itself, it has to do with what the D is doing with calcium. Vitamin D helps absorb calcium into the blood by 20 times.

This is very rare for this to happen and you would have to have very high levels of vitamin D. If you have taken a smaller amount, it’s not gonna happen. The first symptom of the high level of vitamin D is hypercalcemia which is the term used for high calcium in the blood as well as constipation, kidney stones, frequent urination, dementia, depression, ulcers, abdominal pain and even arrhythmia.

One of the challenges with vitamin D in relationship to calcium is that it doesn’t tell the calcium where to go. So D is only about increasing the calcium in the blood and it stays there. So there is a  simple solution. Take vitamin K2. Vitamin K2 triggers a protein that tells the calcium to go into the bone to come out of the soft tissues and into the bone.

Also, avoid dairy. If you avoid foods high in calcium like dairy then you’re going to get the benefit of the D3 without this calcium problem. Next, you can just take magnesium that will also help balance the calcium and drink more water to actually help prevent the kidney stones.

Read More: How Vitamin D Works in the Body

Vitamin D3 and Vitamin D2 (Video)

Doctor Mike Hansen


  • Updated August 9, 2020