What is vitamin deficiency: symptoms, causes & prevention

Vitamin deficiency refers to a deficiency in certain vitamins including vitamins B12, C, D and folate. This can occur due to a diet not containing enough of these vitamins, or the result of a condition affecting the body’s ability to absorb and / or process them. Vitamin deficiency anaemia can lead to serious health complications as a result of a lack of healthy red blood cells. Unfortunately, vitamin deficiency can remain undetected for years and cause damage before it is diagnosed. Knowing your vitamin levels can help avoid this and help you seek advice on any deficiency discovered.

What is vitamin deficiency?

Vitamin deficiency is a low level of a particular vitamin including the following:

  • Vitamin B12, also called ‘cobalamin’, which plays an important role in the production of red blood cells and DNA, as well as supporting our nervous system. A deficiency can cause your body to make abnormally large red blood cells that cannot function correctly (megaloblastic anaemia). Vitamin B12 is acquired through diet and is found in animal produce.
  • Folate, also called vitamin B9, is also essential in keeping our nerves and red blood cells healthy. Folate is also acquired through diet and as for vitamin B12, a deficiency can cause megaloblastic anaemia.
  • Vitamin C plays a key part in the growth and repair of skin, blood vessels, bones and cartilage. A deficiency may rarely lead to a condition called scurvy, which causes excessive bruising, bleeding, and muscle and joint pain.
  • Vitamin D, its main role is to help regulate the amount of phosphate and calcium in the body, which is needed to keep bones, teeth and muscles healthy.

In order to avoid vitamin deficiency anaemia, it is recommended that your intake of vitamins is in line with the following daily recommended intake for adults:

  • Vitamin B12: 5 micrograms
  • Folate: 200 micrograms
  • Vitamin C: 40milligrams
  • Vitamin D: 10 micrograms

What are the symptoms of a vitamin deficiency?

As the symptoms of vitamin deficiency develop slowly and are extremely varied, it can take months, or even years, before a deficiency is recognised. These symptoms include the following:

  • Fatigue
  • Headaches
  • Shortness of breath
  • Dizziness
  • Pins and needles
  • Impaired vision
  • Numbness or tingling in your hands and feet
  • Muscle weakness
  • Personality changes
  • Unsteady movements
  • Memory loss / confusion

What are the causes of a vitamin deficiency?

The main causes of vitamin deficiency include the following:

  • Poor or restricted diet: A healthy and balanced diet that contains a variety of fruit and vegetables together with animal produce should be sufficient to get most of the vitamins you need. However, an unhealthy diet lacking variety and low in fruit and vegetables can lead to vitamin deficiency. People who are on a vegetarian or vegan diet can suffer from deficiencies of vitamins that come mainly from animal produce such as vitamin B12. Overcooking food can also result in deficiency as it can cause the vitamin content to diminish.
  • Medical conditions: health conditions such as atrophic gastritis (chronic inflammation of the stomach lining), Crohn’s disease and Coeliac disease can affect your body’s ability to absorb and/or process vitamins.
  • Medications: Certain drugs such as heartburn medications, anti-seizure drugs, anti-acids and diabetes medications can prevent your body from absorbing enough vitamins.
  • Pregnancy: Pregnant women are recommended to take a supplement of 400 micrograms of folate for the first 12 weeks of pregnancy, and a supplement of 10 micrograms of vitamin D whilst pregnant or breastfeeding.

How to help prevent vitamin deficiency

Certain lifestyle changes can help prevent vitamin deficiency. These include:

Diet modifications

In order to ensure you are getting enough vitamins through your diet, you should eat a varied healthy diet including:

Folate-rich foods Vitamin B12-rich foods Vitamin C-rich foods
Dark leafy greens




Fortified breakfast cereals







B12 Fortified foods


Citrus fruit


Bell peppers


Dark leafy greens

Quitting smoking

Some studies have found smoking can increase your chances of vitamin deficiency as it interferes with the absorption of nutrients. Smoking is the leading cause of preventable death in the UK and contributes to lung cancer and coronary heart disease. If you are a smoker and want to quit the habit, you can find practical tips and advice here: Simple tips to help quit smoking.

How can I raise my vitamin levels fast?

People with vitamin deficiency may need to have injections from their GP or a specialist in order to quickly raise their levels.

Is vitamin deficiency serious?

Vitamin deficiency can be serious and have cause severe complications such as anaemia, bone damage and nerve damage.

What is considered low vitamin levels?

The ‘normal’ range of vitamins varies between laboratories. However, as a guide, typical ‘normal’ ranges in the UK are:

  • Vitamin B12: between 180 to 700 ng/L. What is a clinically normal level is not clear but it is thought that a level below 200 ng/L identifies 97% of people with B12 deficiency.
  • Vitamin C: People with a level below 30 nmol/L are considered to have a deficiency in vitamin C. People with a level of between 30/50 nmol/L may be deficient in vitamin C
  • Folate: Less than 5μg/L.
  • Vitamin D: Above or equal to 25 nmol/L.

How long does it take to recover from a vitamin deficiency?

Once treatment begins, vitamin deficiency symptoms can improve within days or a few weeks though some complications, such as nerve damage, can be permanent.

A Bluecrest home test kit can measure your levels quickly and easily. It’s a simple finger prick test that takes minutes to do and you’ll get results in as little as 8 days. For more information on diet and nutrition, you can visit the Bluecrest blog.