The first article of the year and the penultimate article in my nutrition series focuses on Vitamins.
What are vitamins and what do I need them for?
Vitamins are a group of organic compounds that are vital for sustaining life of organisms. Any compound that cannot be produced by the body in sufficient quantities are labelled vitamins. So this means that some vitamins aren't vitamins to other animals, Vitamin C is a prime example. In a well constructed balanced diet the body gets all the required vitamins from the food consumed, however supplementation is sometimes need, like in people with low Vitamin B-complex or in countries which suffer long periods of darkness and thus less Vitamin D absorption. As they are chemically based, they can be produced synthetically.
There are currently 13 worldwide recognised vitamins and the human body needs a certain amount of all of these in other to help growth and strength of bones, skin and hair, protection from diseases and many other functions.
Vitamin A
Vitamin A is important for the development of children, resisting infection and helping eyesight, especially night vision. It is found within fatty foods and those foods containing carotene, like carrots. Dark green vegetables are also high in Vitamin A as they contain high concentrations of carotene which is masked by the greenness. Fish liver oils normally contain the most Vitamin A per gram. Diary products also contain Vitamin A but the amount varies on numerous factors, the Summer months are normally the best for Vitamin A as the cattle graze on fresh forage Foods containing Vitamin A should be stored in low-non light conditions and in cool, dry areas as carotene is destroyed by light.
Taking too much Vitamin A can result in Hypervitaminosis A. This can cause problems with skeletal development and with vitamin metabolism, as well as other minor ailments. However, unless you are a child or elderly, then the chances of overdosing on Vitamin A are slim.
Vitamin B
Vitamin B was originally thought to be just one substance but further research has found that it can be broken down into eight individual substances. The three main ones are Thiamin (B1), Riboflavin (B2) and Nicotinic acid or Niacin (B3). It is used by the body for maintaining of the nervous system, allowing the body to process carbohydrates and break them down for energy and encouraging growth. It should also be noted that Vitamin B is water soluble and so it can be lost during cooking, high temperatures and bicarbonate of soda also destroy Vitamin B. Riboflavin is quite resistant to high temperatures but bright sunlight (or equivalent) will result in it breaking down. Good sources for Vitamin B are grains, pulses, beans, potatoes, bananas, tuna, turkey and liver.
There are various side effects from being deficient or overdosing on Vitamin B ranging from sore throat and rashes to mania and neurological damage. However, most people within the Western World get enough Vitamin B within their daily diet without the need to add more.
Vitamin C
Vitamin C is an antioxidant and is produced internally by many organisms, however Humans is not one of them. It is essential that Humans get enough Vitamin C in their diet as it is needed for child development, helping the healing of the body and fighting diseases especially in mouth and gum infections. Vitamin C can be lost when cooking or soaking in water, also never use bicarbonate of soda when cooking vegetables or fruits. Also bad storage will reduce the amount of Vitamin C in a product, length of time, bad ventilation, too warm and bruising are the main causes. Also be careful of cutting your vegetables and fruits into too small pieces as this will effect the Vitamin C levels.
Generally the majority of our Vitamin C comes from plant based sources. Even though the exact amount varies depending on climate it was grown in, soil it was planted in, when it was picked, how it was stored etc, some of the better sources are oranges, tomatoes, lemons, limes, grapefruit, seabuckthorn and chillies. As most animals synthesize their own vitamin C, it stands to reason that we can gather sources of Vitamin C from animal products. It is most present within the liver but as most of the meat sources we use in our diet are from the muscle, it means we shouldn't rely on it for our Vitamin C intake. The best sources for animal based Vitamin C is calf liver, beef liver, raw oysters and cod roe. Basically any offal is a source of Vitamin C but it is greatly reduced in comparison to plant based sources.
On a side note, the nickname for British, Limeys, comes from the days of the 19th century. The Royal Navy added lime juice to the sailor's daily ration of watered down rum (known as grog) so it would make the stored, stagnant water more palatable. This had the added effect of starving off scurvy (a side effect of too little Vitamin C) and making the Royal Navy sailors to healthiest in the world.
Vitamin D
Vitamin D is a very important vitamin for ourselves. Without it, our body's would start lacking from calcium which is important for our bones and teeth. The biggest source for Vitamin D is sunlight, as much as 75% of our Vitamin D comes from our exposer to sunlight. Very few foods contain Vitamin D and so it is important that people get out in the light. Lack of Vitamin D causes problems such as rickets and depression. The majoirty of people get enough natural light that a deficiently isn't a problem but in countries above the 60th parallel (Nordic, Provinces in Canada, parts of Russia etc.) then alternatives are needed, some of these come in the form of tablets or special lights.
The best foods that do contain sufficient amounts of Vitamin D are fish-liver oils, oily fish (Salmon, Tuna, Herring, Sardines etc.) egg yolks and some dairy products. Vitamin D is a very hardy substances and so isn't lost during cooking.
Vitamin E
Vitamin E is a lesser known vitamin and is mainly used by our bodies as an antioxidant, it also helps muscle growth and neurological function. As it is fat soluble, it is found mainly within oils like Sunflower, Wheat Germ, Nut and Olive. It is very rare to not get enough Vitamin E, however when it happens it has been linked to sterility and anaemia.
Vitamin K
Vitamin K is another lesser known vitamin and is used to help process proteins for blood coagulation, and to a lesser extant, to help bind calcium to bones. Without sufficient amounts of Vitamin K, the body can find itself with uncontrolled bleeding, weakened bone and calcification of soft tissues, like arteries.
Vitamin K is find within green vegetables, mainly kale, spinach, Brussels spouts and cabbage. It can also be found within mature cheeses and chicken liver.
