How many people in the UK have a vitamin deficiency?

Vitamins are nutrients the body requires to carry out necessary functions and processes. Because the body is unable to make most of these vitamins, we must get them from our diet.

The western diet is largely to blame for many of the nutrient deficiencies occurring in countries including the United Kingdom. Poor eating habits can cause us to become deficient in certain nutrients and this can lead to rising healthcare costs.

We looked at some of the data related to vitamins B9, B12 and D to see if the UK population is more likely to be deficient in these nutrients.

Our Findings in Summary

We used a combination of our own internal data and NHS prescription data for this piece of research.

The key findings in summary:

  • Everyone in the UK is at a greater risk of vitamin D deficiency. Over one-fifth of males included in our data had low or borderline low levels, whereas over a quarter of females had low or borderline low levels of vitamin D.
  • Vegans, vegetarians and females are most at risk of vitamin B12 deficiency.
  • Vegans/vegetarians are less likely to have folate deficiency due to their abundance in many natural foods.
  • In 2017, the cost of vitamin D prescriptions had risen by 48% since 2015.

Vitamin D

Vitamin D is essential for healthy muscles and bones. However, it is a unique nutrient because although there are some dietary sources of the vitamin, our body can make its own. It does this through sunlight exposure and therefore it is sometimes called the ‘sunshine vitamin’.

However, because of where the UK is located and the reduced levels of sunshine it receives during the winter months, the UK population is at a greater risk of deficiency.

Forth’s statistics reveal that the average vitamin D result is 71nmol/L with just over a quarter of results being low or borderline low. On average women had a slightly lower level than men at 68nmol/L.

A chart showing how many people have low levels of Vitamin D

Both males and females are at risk of vitamin D deficiency in the UK and it can have major health consequences for both genders. Therefore, it is important deficiency is recognised and treated to avoid possible complications.

Vitamin B12

Vitamin B12 is essential for the normal functioning of the immune system as well as the production of red blood cells. According to Nice, the prevalence of vitamin B12 deficiency in the UK, is relatively low, at approximately 6% in individuals aged below 60. This corresponds with Forth’s blood test data, although those who are mostly likely to be more susceptible to deficiency are those following a plant based diet at just over 6.5%, whilst men are at the lowest risk of B12 deficiency at 2.07%.

Table 2. Vitamin B12 status in the UK according to gender


Age range

Reference range

Average result

% low or borderline low

All results


37.5 - 188




all ages

37.5 - 188




all ages

37.5 - 188




all ages

37.5 - 188




Folate also is known as vitamin B9 works with vitamin B12 to produce healthy red blood cells. If either vitamin is deficient, it can cause abnormally large red blood cells, a condition called macrocytic anaemia. It’s naturally found in many foods like green leafy vegetables.

Our results show vegans and vegetarians are least likely to develop folate deficiency because they had the lowest percentage of low or borderline low levels. Male and female results were similar, 8.83 and 8.87 per cent, respectively.

Table 3. Folate (B9) status in the UK


Age range

Reference range

Average result

% low or borderline low

% in the lower quartile of the normal range

All results







all ages






all ages





How much do vitamin deficiencies cost the NHS?

Vitamin D prescriptions

  • Huge growth in Vitamin D prescriptions.
  • According to NHS data in June 2014, there were 1,561,661 prescriptions compared to 2,167,054 prescriptions in May 2019, an increase of 39%.
  • Although the overall cost of Vitamin D prescriptions has increased from  £7,260,851 in June 2014 to £8,547,170 in May 2019, the cost per prescription has decreased.
  • In 2016, The Scientific Advisory Committee on Nutrition published their recommendations for vitamin D, recommending everyone over 1-years-old needed a reference nutrient intake of 10 micrograms of vitamin D per day.

A chart showing daily vitamin D requirements for babies, children and adults

Vitamin B prescriptions

  • NHS data shows that between June 2014 to May 2018 on average there were 418,913 vitamin B (includes both B9 and B12 data), prescriptions each month.
  • On average the NHS spends £1.9m per month on vitamin B prescriptions

What is vitamin D?

Vitamin D is an essential nutrient which works to maintain calcium levels within the normal range in the human body. Even if you eat enough calcium, but your vitamin D levels are low, your body is unlikely to be able to absorb the calcium into your bones where it is vital. Therefore, having low vitamin D levels or being deficient increases the risk of low bone mineral density and fractures.

In children, low levels of vitamin D can result in rickets, a condition which causes permanent bone deformities, weak muscles and reduced growth.

Vitamin D is unique because our skin can make it once it has been exposed to the UVB rays of the sun. There are some food sources of the nutrient, but if you were to eat them and not expose your skin to sunlight, you would most probably be deficient. Because the UK’s sunlight exposure can vary, the population, in general, is at a greater risk of deficiency. 

A chart showing those at risk of vitamin D deficiency

How to improve your vitamin D status?

Improving your vitamin D status is easier between April and September because there is a lot more sunshine. Although, there is no need to sunbathe avidly without any sun protection. This is not safe and increases the risk of developing skin cancer. Your skin can make vitamin D from exposed skin, for instance, hands, face arms and legs, but always remember to be safe in the sun.

Vitamin D is stored in the body and so, we can use it during the autumn and winter months. However, these stores can run out and the foods which contain vitamin D do not have enough to keep up with demand. Therefore, the best way to ensure you have adequate vitamin D is to supplement it. Everyone in the UK should take a supplement which contains 10 micrograms of vitamin per day.

Vitamin D rich food sources include:

  • Oily fish – salmon, mackerel, kippers, trout, eels
  • Cod liver oil
  • Egg yolks
  • Meat
  • Milk
  • Fortified breakfast cereals.

A chart showing the sources of vitamin D.

What is vitamin B12?

Vitamin B12 is essential for the normal function of the nervous system, the metabolism of folate and to produce red blood cells. It also works with vitamins B6 and folate to maintain normal blood homocysteine levels. Increased homocysteine levels are a risk factor for developing cardiovascular disease. 

Vegans are at a greater risk of vitamin B12 deficiency because it largely comes from animal-derived foods. Both deficiencies in B12 and in folate are also ore common in the older population and poor diet can be a factor. According to the NHS, 1 in 20 people aged 65-74 are affected.

How to improve your vitamin B12 status?

Vitamin B12 is present in nearly all foods from an animal source such as:

  • Meat
  • Fish
  • Milk
  • Eggs
  • Cheese

However, vegans and vegetarians who choose not to eat animal products are at a greater risk of deficiency. So, too are older people who may not be following a healthy, balanced diet. New research shows young women may also be at risk, particularly if they follow fad diets and reduce their meat intake. Younger adults, in general, are more susceptible to micronutrient deficiencies.

Some vegan-friendly sources of vitamin B12 include:

  • Yeast extract like Marmite
  • Fortifies breakfast cereals
  • Some fortified soy products

If your levels are low then you may need to consider supplementation. But you should consult medical advice before taking any new supplements.

What is folate?

Folate is an example of an essential vitamin. In other words, the body is unable to make it and so it must be acquired through the diet. It is naturally present in many foods and folic acid is readily available as a supplement.

In women of reproductive age, folate levels are particularly important because deficiency or just not having enough can cause neural tube defects in children such as spina bifida.

It can also cause megaloblastic anaemia in adults and children because DNA is unable to be made properly and cells don’t divide as they should.

How to improve folate status?

Folate is found in many foods including:

  • Broccoli
  • Brussels sprouts
  • Peas
  • Chickpeas
  • Leafy green vegetables
  • Liver
  • Fortified breakfast cereals

Women who are pregnant, trying for a baby or could get pregnant need to take a 400-microgram supplement every day until 12 weeks pregnant.


  • Vitamin deficiencies can affect anyone at any age.
  • Everyone in the UK is at risk of vitamin D deficiency and should supplement their intake with a supplement containing 10 micrograms.
  • Vegans are at a greater risk of vitamin B12 deficiency but are more likely to have adequate folate levels.
  • Women who are looking to get pregnant or are pregnant need to supplement their folate intake with a folic acid supplement daily until 12 weeks pregnant.
  • Vitamin prescriptions have risen dramatically since 2015.


Cashman, K, D et al. (2016). Vitamin D Deficiency in Europe: Pandemic? The American Journal of Clinical Nutrition: 103(4), pp 1033-1044.

Derbyshire, E. (2018). Micronutrient Intakes of British Adults Across Mid-Life: A Secondary Analysis of the UK National Diet and Nutrition Survey. Front. Nutr: 5(55).

NHS. (2017). B Vitamins and Folic Acid. Available at:

NHS. (2019). Overview Vitamin B12 or Folate Deficiency Anaemia. Available at:

Rogers, L. M et al. (2018). Global folate status in women of reproductive age: a systematic review with emphasis on methodological issues. Annals of the New York Academy of Sciences, 1431(1), pp 35–57.

Webb, A, R et al. (2018). Colour Counts: Sunlight and Skin Type as Drivers of Vitamin D Deficiency at UK Latitudes. Nutrients: 10(4).