Foods are not ‘pure’ substances. Although referred to as protein foods, or carbohydrate foods, this only recognized the food to be high in a particular nutrient. In fact, foods are mixtures of different nutrients and other chemical substances such as toxins, pigments and additives. Protein, carbohydrates and fat are regarded as macronutrients due to the size of their molecules. These nutrients are needed in large quantities in the body to enable the body to function properly. Vitamins and minerals are required in lesser amounts but are equally necessary and must be obtained from the food consumed. These are known as micronutrients.
The term ‘vitamin’ was derived from ‘vitamine’, a combination word made up by a Polish scientist, Casimir Funk, from vital and amine meaning amine of life, because it was suggested in 1912 that the organic micronutrient food factors that prevent beriberi and perhaps other similar dietary-deficiency diseases might be chemical amines. This proved incorrect for the micronutrient class, and was shortened to vitamin. A vitamin is an organic compound required as a nutrient in tiny amounts. It is essential for our body to consume a sufficient amount of vitamins because our body is not able to make the vitamin; therefore it is required to be obtained from the diet.
The value of eating foods that helped maintain healthy was recognised long before vitamins were identified. Gradually people recognised the value of foods that were vitamin-rich, yet at that time they were not able to identify the actual vitamins. The ancient Egyptians knew that giving liver to a patient would help prevent night blindness, an illness which was later discovered to be caused by a vitamin A deficiency. The ocean voyages during the Renaissance made it hard to access to fresh fruits and vegetables, which made illnesses common among ship crews from lack of vitamins. In 1749, a Scottish surgeon James Lind, discovered that citrus food helped prevent a deadly disease, scurvy, in where collagen is not formed properly causing poor wound healing, bleeding of the gum’s, severe pain, and death. In the early 20th century, the medical theory found out the scurvy was caused by ‘tainted’ canned food. In the early 19th century, scientists were able to separate and identify a number of vitamins. Lipid from fish oil was used to cure rickets and rats. As technology improved over the century, nutritionists and scientists have been able to identify the vitamins and their function in the body, new vitamins and different types of vitamins have been discovered each day.
The amount of vitamins a person needs daily depends on the person themselves- stage of life, lifestyle, and eating habits. In general growing adolescents, pregnant and breastfeeding women need a higher quantity of vitamins. An approximation of the daily vitamin intake for an average men and women:
| Average Adult| | Average Adult|
Vitamin A| 3675mg| Vitamin B5| 10mg|
Vitamin C| 60mg| Vitamin B6| 2mg|
Vitamin D| 294mg| Vitamin B9| 0.4mg|
Thiamine B1| 1.5mg| Vitamin B12| 0.006mg|
Riboflavin B2| 1.7mg| | |
Niacin B3| 20mg| | |
* Butter, Milk, cheese
* Liver and Kidney,
* Green leafy vegetables (spinach, Brussels sprouts)
* Orange-yellow vegetables (carrots, pumpkin, sweet potato, mangoes, rockmelons) Function;
* Protects the epithelial tissues from infection, including cornea and conjunctiva of the eyes, the respiratory, digestive, and excretory lining of mucus membrane. * Protects the tissue’s surface of the skin
* Helps in normal growth of bones and teeth
Deficiency of Vitamin A;
* Lead to children developing at slower rate
* Increase in infections of the respiratory, digestive tract, and the excretory * Dry skin
* Cornea of the eye becomes dry and irritated