Vitamins are organic compounds which provide a range of functions in the body, including the growth and development of muscles and bones.
There are 13 vitamins:
With the exception of vitamin D, the body cannot make vitamins itself, so we rely on our diet to provide the right amount of vitamins. Eating a varied and balanced diet is an effective way of obtaining almost all of the vitamins we need to maintain good health.
Vitamin D is the only vitamin which our body makes itself. When exposed to UVB radiation from the sun, cells in the skin called keratinocytes convert 7-DHC (dehydrocholesterol) into the pre-vitamin D3.
Each vitamin plays a different role in the body. For example, vitamin C is well known for the treatment of scurvy - a condition caused by a vitamin C deficiency. Vitamin B12 is used by cells all over the human body which aids in the production of DNA and catalyses enzymatic reactions (speeds up reactions in the body).
Most people do not need to take vitamin supplements, so long as they are eating a healthy and balanced diet.
However, some vitamin supplements are recommended for people with certain vitamin deficiencies or with certain medical conditions.
The NHS recommend that children aged between 6 months a 5 years take a daily multi-vitamin supplement. For advice on whether your child should take a vitamin supplement, speak to your doctor.
Public Health England (PHE) advise people to take vitamin D supplements during the months between October and March. Due to the dwindling sunlight during the colder months, the body doesn't produce as much vitamin D as it does during the spring and summer months.
Strict vegetarians and vegans are often advised to take vitamin B12 supplements. Vitamin B12 can prevent anaemia, eye diseases and osteoporosis.
Women who are pregnant, or trying to conceive, are recommended to take 400 mcg of folic acid. According to the NHS, you should start taking it before you stop using contraception. Folic acid is crucial while your child is developing and can reduce the chance of neural tube defects, such as spina bifida. It's always best to speak to your doctor before taking any health supplements if you are pregnant or plan on becoming pregnant.
If you are unsure whether you should take vitamin supplements, speak to your doctor. Depending on your diet and lifestyle, you may benefit from taking a vitamin supplement. For example, people who live a vegan diet are at a higher risk of developing a vitamin-b12 deficiency, so should consider taking a supplement of vitamin-b12.
While not strictly classed as vitamins, other mineral supplements such as zinc, calcium, and iron may also be beneficial alongside a healthy and balanced diet. Some foods are fortified with these metals - this means the food has added minerals.
Always speak to your doctor about vitamin and mineral supplements before taking them.
A vitamin deficiency is a lack of vitamins which the body needs to function normally. In many cases, the deficiency is caused by diet, such as not eating enough of a certain food group. Contrarily, deficiencies can be caused by malabsorption in the body. This is when the body is unable to process the vitamins effectively and so they are not absorbed properly.
Different vitamin deficiencies have varying effects on the body. For example, a lack of vitamin C can cause scurvy, resulting in symptoms such as swollen, bleeding gums, weakness and red or blue spots on the shins. A lack of vitamin A can affect vision, making it harder to see in the dark or, in extreme cases, cause blindness.
If you develop any symptoms which may be attributed to a vitamin deficiency, speak to your doctor.
Vitamin deficiencies are usually diagnosed with a blood test. You can get vitamin deficiency tests on the NHS. These are usually conducted by a healthcare professional in a clinic or hospital. A nurse or doctor will collect a venous blood sample. According to NICE, vitamin deficiency tests are usually reserved for those who present specific symptoms.
Alternatively, you can buy vitamin deficiency tests privately from online pharmacies and test centres. These tests are usually conducted by yourself at home. They involve collecting a blood sample from your finger using a lancet.
You can discuss your results with a healthcare professional. They will be able to determine whether you need need to take a vitamin supplement or make adjustments to your diet and lifestyle.
Vitamin supplements are available in a number of different formulations.
Tablets and capsules are the most common form of vitamin supplement. These are usually swallowed whole with water. However, some people may have difficulty swallowing tablets. If you have difficulty swallowing tablets, speak to a pharmacist about other formulations available.
Some vitamins have chewable variations available. These are usually flavoured and are available for both adults and children. Chewable vitamins, particularly those made for children, may contain high amounts of sugar. Always check the label or ask a pharmacist if you are concerned about the amount of sugar in a vitamin supplement.
Effervescent vitamins are a popular formulation as they make it easier to take. These vitamin supplements are dissolved in water to create a drink. Much like chewable tablets, they are often flavoured to make them more palatable. However, effervescent tablets can contain high amounts of salt. If you have been told to cut down on your salt intake, speak to your doctor before taking effervescent tablets.
Aside from individual vitamins, which are often used to treat specific vitamin deficiencies, there are multi-vitamins which combined several vitamins and minerals into one tablet.
Multi-vitamins may be marketed in a number of different ways. Some are formulated to boost the health of men and women in different ways. Others may be designed to boost the immune system and keep the body's defences strong. Your doctor may recommend a multi-vitamin during pregnancy or during the winter to ensure your body is getting the right amount of vitamins and minerals.
Different multi-vitamins contain varying amounts of different vitamins. Some may contain more vitamin A or vitamin C. Moreover, multi-vitamins may also contain minerals like iron and zinc.
You can find the list of vitamins and minerals on the packaging. Sometimes, the amount of each vitamin is listed in either international units (IU) or milligrams (mg) and micrograms (mcg).
Generally, most vitamin supplements are available over the counter from pharmacies, health food shops and supermarkets. They may offer different formulations, such as tablets, capsules or liquids.
Before you take any vitamin supplement, it's important to speak to your doctor. Vitamin supplements can interfere with other medicines you may already be taking. Your doctor may be able to suggest which vitamin supplements to take.
Some vitamin supplements, such as Fultium D3, are only available on prescription and are used to treat a diagnosed vitamin deficiency.
Taking a multivitamin every day is perfectly safe when taken alongside a balanced and nutritious diet.
For the most part, you can obtain most of the vitamins and minerals your body needs through a healthy and balanced diet. However, there are some vitamins which we can't get enough of with diet alone, such as vitamin D.
While you can take vitamins at any time of day, some vitamins like B vitamins (B2, B6 and B12) are best to take in the morning.
It is unlikely that vitamins cause weight gain when taken alongside a healthy and balanced diet.
Some of the most essential vitamins include vitamin C, vitamin D, calcium, zinc, iron and vitamin B12. Many multivitamins contain these vitamins, though you shouldn't rely on a multivitamin as the main source of these minerals.
It is recommended to take 400mcg of folic acid during pregnancy to reduce risks during the first 12 weeks of pregnancy. You should also consider taking vitamin D during pregnancy.
During pregnancy, you should avoid taking vitamin A as this can harm your baby.
You should always speak to your doctor or a pharmacist before taking any vitamin supplements during pregnancy.
Some vitamin supplements, particularly high dosage vitamins, are only available on prescription.
Most vitamin supplements are available over the counter from pharmacies, health food shops, supermarkets and online vendors such as Prescription Doctor.
Children may benefit from a multivitamin to ensure they are getting their daily recommended intake of vitamins and minerals.
The UK government recommend that children aged between 6 months and 5 years take a vitamin supplement which contains vitamin A, vitamin C and vitamin D.
Babies who are taking in more than 500ml of formula do not need to take vitamin supplements. This is because formula milk is fortified with vitamins A, C and D.
You should always speak to your doctor or a pharmacist before giving your child a vitamin supplement.
Table of contents
NHS, 2020. Vitamins and minerals.
NHS, 2021. Vitamins for children.
NHS, 2020. Vitamins, supplements and nutrition in pregnancy.