Vitamins can be broken into two groups – Fat soluble and water soluble. The Fat Soluble vitamins are Vitamins A, D, E and K. They are stored in the liver so unlike water soluble vitamins, (B vitamins and Vitamin C) they are not always needed every day.
Vitamin A – Retinol and Beta Carotene
Retinol and beta-carotene are often referred to as Vitamin A. There is a difference however, beta-carotene is from plant origin and needs to be converted in the body to vitamin A and retinol is from meat or animal origin and does not need to be converted.
Sources of Vitamin A
Animal Sources of Vitamin A – Liver, Kidney and Fish – especially fish liver i.e. cod liver oil
Animal Product Sources – Cheese – (Especially Cheddar), Butter, Milk and Eggs, Skimmed milk contains little or no Vitamin A unless it is fortified (added).
Plant or Vegetable Sources – Carrots, Peppers, Apricots (Dried and Fresh), Mango and Green Leafy vegetables such as cabbage, spinach and Kale.
The Darker green the vegetable the higher in beta-carotene (Vitamin A) so the outside of a cabbage will contain more than the paler inside.
How much is needed?
It is hard to not have enough vitamin A the Average UK intake for men and women is 1030 micrograms and the recommended daily intake is 600-700 micrograms. This is hardly surprising as one medium portion of carrots contains over 700 micrograms of vitamin A (as beta-carotene).
Lack of Vitamin A can lead to loss of vision in dim light and it is essential for healthy skin and hair.
Vitamin A can build up in the liver so it is much safer to take it from food sources than vitamin pills. Vitamin A should not be supplemented if you are pregnant or planning to have children as it can cause birth defects. Also smokers should not take beta-carotene supplements as it has been linked
You may read about beta-carotene as a ‘precursor’ to vitamin A. Put simply this means vitamin A can be made from Beta – Carotene.
B-Vitamins
B Vitamins are water soluble vitamins and are often grouped together they are as follows-
Thiamin, B1 – Releases energy from carbohydrates and lack of it can lead to a condition known as beriberi. Thiamin is found in abundance in brown-rice and other whole-grains. Beriberi was widespread in Japan and China around 19th and early 20th Century, this marked the introduction of the steam-powered rice polisher which removed the nutritious outer casing of rice.
Thiamin is found in whole grains – i.e. brown rice, brown, wholemeal and wheatgerm bread and wholemeal pasta. It is also found in milk, pork, vegetables and fruit.
Thiamin is widespread and deficiencies are rare, the average UK intake is 1.29mg and the recommended daily intake is between 0.7mg and 1.1mg depending on sex and age.
Alcoholics and heavy drinkers need more thiamin than the general population as alcohol depletes it in the body.
Vitamin B2 Riboflavin
Riboflavin is in many foods such as, dairy products, meat, fish and vegetables such as asparagus and broccoli. Deficiency is rare as it is so widely distributed, the recommended daily intake is between 1.1 and 1.3 mg a day and the average UK intake is 1.61mg. However vegans can find they are deficient and the tell-tail signs of riboflavin deficiency are sores at the side of the mouth. Deficiency can be a problem in children as it may prevent proper growth.
Niacin
Niacin is used to utilize energy. Deficiency can result in a disease know as pellagra where the skin can become dark and scaly. The best sources are Fortified breakfast cereals, chicken, wholemeal and wheatgerm bread and cheddar cheese.
The recommended daily intake for niacin is between 12 and 18mg and the average daily intake in the UK is 25.3mgs.
Folate, Pathothenic acid and Biotin
Folate supplements should be taken by pregnant women and women planning to have children as it prevents their unborn child developing birth defects such as spina bifida. Like biotin one of the best sources for folate is fortified breakfast cereals, bread and yeast extract. Biotin which is essential for the metabolism of fat is also found in egg yolks, fish, fruit and vegetables and dairy products.
Pathothenic is necessary for the release of energy from carbohydrates. It is found in such a wide variety of foods that it is hard to develop a deficiency.