The list of vitamins is quite extensive but in this post you will learn everything you need to know about vitamins. In a prior post I went over what vitamins are, their function and some more information on antioxidants. If you haven’t yet read it, it may be worth reading it to get a full understanding of what vitamins are and what they do within our body.
Download the complete list of vitamins and their functions
If you are worried that you are facing any kind of deficiency, please check out the nutritional therapy programs and dietary analysis that can truly identify if you have anything to worry about. There are also certain lab tests that can give you even more accurate answers, like the nutritional blood test or allergy screening test.
Lets firstly go over the meaning of recommended values. You will be able to spot that on food labels now.
The recommended intakes of vitamins.
The following recommended values will fall under the below 4 categories introduced by the UK government.
- Dietary Reference Values (DRVs) provide a recommended range of nutritional intake for each nutrient. The DRV ranges meet the needs of every individual by providing lower, medium and higher average amount of each nutrient.
- Lower Reference Nutrient Intake (LRNI) is the lowest amount of each nutrient recommended for intake. It will only be enough for approx.2.5% of the population whose requirements are low.
- Reference Nutrient Intake (RNI) is the upper amount of each nutrient recommended for intake. It is enough to ensure 95% of the UK’s population needs are met.
- Estimated Average Requirement (EAR) is the estimated average and is sufficient for 50% of the UK’s population’s needs being met.
** Mcg refers to micrograms. / ** Mg refers to milligrams
As mentioned in the previous article, there are two types of vitamins – Water-soluble and fat-soluble. If you haven’t read the previous article, water-soluble vitamins are vitamins that cannot be stored by our body whereas fat-soluble vitamins can be stored by the body. Therefore, it is unlikely that you will suffer from a deficiency from fat-soluble vitamins.
Vitamin A is essential for vision in the dark, maintains mucous membranes that protect respiratory tract, and maintains healthy skin. Deficiency can result in reduced or complete loss of vision and reduced resistance to infection. Sources of Vitamin A include;
- dried apricots
- soya beans
- dairy products
Excessive amounts can build up in liver and be toxic hence why pregnant woman should seek advice if they want to take supplements. The DRV is 600mcg* per day for females and 700mcg* per day for males.
Vitamin D promotes absorption of calcium and phosphate from food which support healthy bones and teeth, brain nervous system, cellular growth and immune regulation. The main forms of vitamin D are ergocalciferol (D2) and cholecalciferol (D3) and the main source is radiation from the sun. Other sources include;
- liver oil
- Oily fish (salmon/mackerel)
- Fortified foods.
People with dark skins who live in places with limited sunlight or people who cover their skin may struggle to obtain vitamin D. Whereas children aged 6 months to 5 years, pregnant or breastfeeding women, people aged 65 or over and anyone who does not get exposure to sun should consider supplementation. Excess vitamin D can build up in liver and may become toxic. Taking 25mg or less per day is unlikely to cause any harm.
Vitamin E acts as an antioxidant protecting the cell membranes from damage by oxidation (breathing in and out), it comes from a group of substances called tocopherols and tocotrienols. Deficiency can lead to disruption of fat absorption of the vitamin and may lead to the development of a condition affecting the nervous system. Sources of Vitamin E include;
- vegetable oils
- nuts & seeds
Intake of 4-8 mg per day is considered adequate. No specific recommendation has been made due to its closely related link to the intake of polyunsaturated oils.
Vitamin K is essential for the formation of blood-clotting proteins, especially prothrombin. It is synthesised in the gut by the resident bacteria. Sources of vitamin K include;
- Brussels sprouts
Two main sources are phyllo Quinone (K1) and menaquinone (k2). The DRV is set between 0.5 and 1.0 mcg per 1 kg of bodyweight per day. No nasty side effects from having too much natural vitamin K but excessive amounts of synthetic vitamin K can cause breaking down of red blood cells, known as haemolysis and liver damage. More vitamin K is required for new born who don’t have gut flora to produce Vitamin K, condition called ‘haemorrhagic disease’ and people on antibiotics.
What are water-soluble vitamins?
These vitamins work together to facilitate energy production, they cannot be stored in the body apart from vitamin C.
Vitamin C is involved in the formation of collagen, a protein used in the structure of connective tissues and bones which helps keep them together. It helps with wound healing and iron absorption. But it can be destroyed by light, heat, alkali, air, physical processing and cooking. To preserve the vitamin in your food, it should be kept in air tight containers, in a refrigerated or cool location in the dark. The best way to prepare the food to preserve the vitamin C is to stir-fry, steam or microwave.
Vitamin C deficiency can lead to poor wound healing, bone weakening and scurvy (bleeding and swollen gums). Recommended intake is 40mg per day. Any excess is lost in urine but can lead to diarrhoea and kidney stones.
Sources of vitamin C include;
- Kiwi fruit
- Brussels sprouts
Smoking increases the rate at which the body uses vitamin C so if you are a smoker, you are at a higher risk of vitamin C deficiency.
Vitamin B1 (thiamine)
Thiamine is involved in the release of energy pathways in the body. Thiamine is important for the brain and nerves that utilise glucose for all their needs and help support proper heart function. Deficiency of B1 can lead to muscle weakness, nerve damage, heavy legs and headaches. Meanwhile, alcohol reduces the body’s ability to absorb B1 from food so you should avoid consuming alcohol with meals. Sources of B1 include;
- Green vegetables
- Root vegetables
- Fortified cereals
Vitamin B1 requirements are based on energy intakes. The RNI is set at 0.4mg per 1000kcal. Taking too much can result in headaches, irritability, insomnia, a rapid pulse and weakness.
Vitamin B2 (Riboflavin)
Supports the release of energy pathways especially from fat and protein. However, deficiency can cause changes to mucous membrane and in skin around nose and mouth. Various skin conditions are associated with vitamin B deficiency. Sources of vitamin B2 include;
- Yeast extracts
- Milk (milk exposed to sun loses 10% of its B2 vitamin per hour).
- Green vegetables
- Fortified cereal
DRV is 11mg per day for females and 1.3mg per day for males.
Vitamin B3 (Niacin)
Niacin is involved in the energy production, particularly the production and breakdown of glucose (sugars), amino acids, fatty acids and the metabolism of folate and vitamin C. Niacin is also required for the development, maintenance and function of the skin, the digestive system and nervous system and is vital for the manufacture of DNA. Deficiency of B3 can cause pellagra, early symptoms include fatigue, loss of appetite, muscle weakness and anxiety, then can develop into diarrhea, skin rashes and delirium. Sources include;
- Mutton and other meats like fish
- Yeast extract
- Fortified cereals.
Recommended intake is 6.6 mg per 1000 kcal or 12-18mg per day. Excess can cause liver damage.
B6 is a mixture of pyridoxine, pyridoxal and pyridoxamine. This is to say, it is involved in biological reactions like amino acid metabolism, fat metabolism, and supports metabolism of glycogen in muscles, protects against infection and plays a role in production of haemoglobin (a protein which transports oxygen around the body via blood cells). But, deficiency may cause anemia, a smooth tongue, mouth cracks, dermatitis, muscular problems. People who suffer from alcoholism need extra vitamin B6 as alcohol reduces body’s ability to absorb it. People who may consider supplementation of B6 are people on a high protein diet as the vitamin depletes due to metabolism of amino acids, people with medical conditions like asthma, kidney diseases, Hodgkin’s disease, sickle-cell anaemia and diabetes. Sources of B6 include;
- Whole cereals
- Fortified cereal
Moreover, recommended intake is 1.2-1.4mg per day. Excess may result in disturbance in the sensory nervous pathways. Eg, spinal nerves.
B2 is important for normal growth and development so it’s especially important to babies, kids and teenagers and works well with folate in the production of red blood cells. It also assists in protection and normal function of nerve cells, manufacture of DNA and metabolism of fats and carbs. B12 is water-soluble but we are able to store it in the liver. But, deficiency can lead to megaloblastic anemia where red blood cells are abnormally large and inefficient at carrying oxygen. Lack of b12 due to inability to produce intrinsic factor can lead to pernicious anemia. Vegetarians and vegans may need supplements. Sources of b12 include;
- Fish- cod, salmon, haddock, clams, shrimps
- Dairy products – milk
- Fortified cereal
- Yeast extracts
Moreover, Recommended intake RNI is 1.5mcg per day.
Biotin is used as a co-enzyme for the carboxylase enzyme that carries carbon dioxide (CO2) units in the metabolic pathways, and as a result it plays an important role in lipogenesis (the synthesis of fatty acids in the cell) and gluconeogenesis (the formation of glucose from other sources like amino acids) and catabolism (breakdown of branched amino acids). Deficiency include loss of hair. Sources of biotin include;
- egg yolk
- oats and grains
- yellow split peas & green split peas, brown lentils and Lima peas.
Recommended intake is 10-200mcg per day. Any excess is excreted via faeces.
Pantothenic acid- (B5 vitamin)
B5 is vital to the transformation of energy in the cells by assuring an adequate production of healthy fat in our cells. On the other hand, It also helps to change and shape the function of protein and their acids. In addition, it also has a pivotal role in energy production, in the conversion of fats and carbs into usable energy. However, deficiency may lead to low energy, fatigue, dizziness, headaches, muscle weakness and an abnormal sensation in the lower legs and feet. Sources of B5 include;
- meat (especially calf’s liver)
- veg (mushrooms, cauliflower, broccoli, tomatoes, corn)
- sunflower seeds
- low fat yogurt
No specific recommendation for daily intake but for guidance intake is 5.4mcg per day is adequate.
Folate (folic acid)
Folic acid plays an important role in the manufacture of DNA and proteins. Above all, It is also essential for normal growth and development and in the production of new cells. Also works alongside B12 in the production of haemoglobin in red blood cells. However, deficiency can lead to megaloblastic anemia where red blood cells are too large and make carrying oxygen inefficient. Sources include;
- dark green veg (spinach, broccoli, and asparagus)
- nuts and beans
- beets and lentils
- Wholemeal bread.
On another note, pregnant women should avoid liver source as it is high in Vitamin A which at high levels can cause malformations and birth defects in the foetus. RNI is set to 200mcg per day in adults for the first 12 weeks of pregnancy, an additional 500mcg per day is recommended. However, high intakes may hinder absorption of zinc. Therefore, the first 3 months of pregnancy are the most vital where the spinal development occurs and most people do not discover they are pregnant until week 4-6.
In conclusion, if you are suffering from any unusual symptoms like mood swings, regular head aches, stomach aches etc, it may be worth getting a professional opinion. Here, at Nutrition2Change you can find everything you need to improve your health. Please check out nutritional therapy programs as well as lab tests that can give you the answers you are searching for.
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Wyatt KM, Dimmock PW, Jones PW, O’Brien PMS. Efficacy of Vitamin B-6 in the treatment of premenstrual syndrome: a systematic review. BMJ 1999;318:1375-81