Healthy Diet A-Z Of Vitamins


Thousands of people in Britain are at risk of nutrient deficiencies according to the Health & Food Supplements Information Service.[1] Shortfalls of vitamins and minerals across the board are evident, increasing the risk of poor health.


And while nutrients should be obtained from eating a balanced diet, sourcing optimal amounts of nutrients from the diet alone is a challenge. Where people need additional support to meet their nutritional needs, vitamin and mineral supplements provide a reliable source of additional nutrition.

A fish oil supplement should be taken for those following a vegetarian or vegan diet (vegan friendly option) or for those not eating two portions of fish (one of which must be oily) a week.

Public Health Nutritionist Dr Emma Derbyshire takes a look at the some of the vitamins, minerals and essential fats we need in our diet.



Vitamin A: A fat-soluble vitamin, stored mainly in the liver, this vitamin is vital for maintaining good eyesight, particularly for the normal function of the retina and visual adaptation to darkness, and healthy skin. It is also important for immunity, as well as growth in children. The richest natural sources of vitamin A are fish liver oil and it is also very concentrated in animal liver. Other sources include oily fish, egg yolk, cheese, fortified margarine, butter and full fat milk.

Vitamin B12: If you are following a vegan or vegetarian diet you are probably well aware of the need to supplement with Vitamin B12 as it is only found in animal products or fortified foods.  This vitamin is essential in the functioning of the nervous and immune systems; making red blood cells and is involved in energy production.  Good sources of vitamin B12 include meat, liver, kidney, poultry, fish, eggs, dairy products and fortified breakfast cereals.

Vitamin C: Vitamin C is synonymous with colds. It acts as an antioxidant, helping to neutralise free radicals (the baddies in our bodies), so that our body cells are protected. It is also involved in maintaining healthy skin, blood vessels, bones and cartilage. It helps aid wound healing and is also necessary for the function of several enzymes and increases the absorption of iron in the gut. Vitamin C is found in foods of plant origin, particularly citrus and soft fruits (such as oranges, strawberries, kiwi, blackcurrant, guava) and vegetables (such as kale, broccoli, brussels sprouts, peppers, potatoes, tomatoes) are major sources of vitamin C.

Vitamin D: An important vitamin, the body creates this from direct sunlight on the skin. However, Public Health England recommends that during the autumn and winter months we need to take a daily D supplement because the sun isn’t strong enough for the body to make vitamin D. Vitamin D helps the body to absorb and use calcium and phosphorus; which are essential for maintaining strong and healthy bones and teeth, as well as other body functions such as heart and muscle function. It is also important for blood clotting, the immune system and muscle growth, development and function.

Good food sources include full-fat dairy products, oily fish, egg yolks and fortified margarine. However, food alone is unlikely to provide sufficient vitamin D. The Department of Health recommends a daily supplement containing 10 micrograms of vitamin D during winter and then all year round if you aren’t often outdoors.

Vitamin K: A lesser known vitamin, vitamin K is needed for the formation of several of the proteins, called ‘clotting factors’ that regulate blood clotting, which means it helps heal wounds. It is also required for the formation of some proteins which are important for the maintenance of healthy bones and teeth. Vitamin K is found in green vegetables such as kale and spinach, potatoes, liver, soya beans and vegetable oils.

Folic Acid: Known as folate in its natural form, helps the body form healthy red blood cells. And women are advised to take folic acid for 12 weeks prior to conception and to continue taking folic acid supplements until the 12th week of pregnancy.

This is essential during pregnancy for efficient neural tube development which forms the brain and spinal cord. In fact, nine out of ten women have such low intakes of folic acid that if they became pregnant their child would be at risk of neural tube defects.

Good sources of folate include broccoli, brussels sprouts, liver (but avoid this during pregnancy), leafy green vegetables, such as cabbage and spinach, peas, chickpeas, breakfast cereals fortified with folic acid.



Iron: Iron is essential for the formation of haemoglobin which is present in red blood cells. Haemoglobin is being formed in the body all the time and is the substance in red blood cells that transports oxygen around the body.

A lack of iron can lead to iron deficiency anaemia, concave and brittle nails, sore tongue, cracking in the corners of the mouth, increased susceptibility to infection. Also, tiredness, muscle fatigue, skin itching, dizziness, headache, insomnia, brittle hair and hair loss.

Good sources include liver, kidney, heart, red meat, beef, pork, canned pilchards/sardines, fish, shellfish, wholegrain cereals, eggs, spinach, chicken, leafy green vegetables, dried fruit and fortified breakfast cereals.

Calcium: The most abundant mineral in the body, calcium is essential for building and maintaining healthy bones and teeth. Calcium also plays a role in regulating muscle contraction, including the heart muscle; facilitates nerve transmissions; is involved in energy production and cell division and makes sure the blood clots normally.

Long term deficiency leads to osteoporosis, muscle aches and pains, muscle twitching and spasm, muscle cramps; rickets (in children), osteomalacia (softening of bones), heart disorders, brittle nails and insomnia.

Good sources include dairy products, canned fish such as sardines (when the soft, edible bones are consumed), dark green leafy vegetables, white bread, brown bread, sesame seeds and pulses.

Iodine: Iodine is used to form thyroid hormones, which help regulate our body’s metabolic rate – the speed at which chemical reactions take place in the body. Deficiency may lead to hypothyroidism. Symptoms include tiredness, muscle weakness, breast pain and tenderness, sudden or unexplained weight gain. Good sources include saltwater fish and shellfish, kelp, seaweed, sea salt, iodised salt, and dairy products.

Magnesium: The second most abundant nutrient stored in body tissue after calcium. Magnesium is needed for the formation of many enzymes in the body which release energy from food. It is also vital for the nervous system, muscle movement and for the formation of healthy bones and teeth. Magnesium is present in all green plants. The main sources are unrefined cereals and wholemeal bread, green leafy vegetables, and peanuts.

Zinc: An important part of many enzymes, some of which have key roles in the formation of new proteins – one of the processes involved in tissue growth. Zinc is required to aid growth of the immune cells plus maintenance of hair, skin and nails. Superoxide dismutase (a powerful antioxidant enzyme that neutralises potentially damaging free radicals) requires zinc. Zinc is also essential for reproduction.

Signs of mild to moderate deficiency include growth retardation, male hypogonadism (the testes produce few or no sex hormones), poor appetite, rough skin, mental lethargy, delayed wound healing and impaired taste. Good sources include red meat, liver, shellfish (especially oysters), egg yolks, dairy products, wholegrain cereals and pulses.



Cod Liver Oil: Cod liver oil and other fish liver oils are rich sources of vitamins A & D; they are also rich sources of the omega-3 essential fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). EPA and DHA are found in every cell membrane in the body and have a wide range of functions.  Their health benefits include1: helping to reduce triglyceride levels in the blood, heart health, supporting brain function, reducing blood pressure, maintaining eye health.

Fish body oils and fish liver oils are widely used in the management of inflammatory joint conditions[2], and omega 3 fatty acids also help maintain suppleness.


[1]HSIS: State of The Nation, published Autumn 2019 and inclusive of

[2] Natural Medicines Comprehensive Database, via the National Library of Medicines National Institutes of Health