Vitamins are organic compounds which are needed in small quantities to sustain life. We get vitamins from food, because the human body either does not produce enough of them, or none at all.
An organic compound contains carbon. When an organism (living thing) cannot produce enough of an organic chemical compound that it needs in tiny amounts, and has to get it from food, it is called a vitamin.
Sometimes the compound is a vitamin for a human but not for some other animals. For example, vitamin C (ascorbic acid) is a vitamin for humans but not for dogs, because dogs can produce (synthesize) enough for their own needs, while humans cannot.
Contents of this article:
What are vitamins?
A vitamin is one of a group of organic substances, present in minute amounts in natural foodstuffs, that are essential to normal metabolism; insufficient amounts in the diet may cause deficiency diseases.
Put simply, a vitamin is both:
- An organic compound (contains carbon).
- An essential nutrient the body cannot produce enough of on its own, so it has to get it (tiny amounts) from food.
There are currently 13 recognized vitamins.
Fat soluble and water soluble vitamins
There are fat-soluble and water-soluble vitamins.
Fat-soluble vitamins are stored in the fat tissues of our bodies, as well as the liver. Fat-soluble vitamins are easier to store than water-soluble ones, and can stay in the body as reserves for days, some of them for months.1
Fat-soluble vitamins are absorbed through the intestinal tract with the help of fats (lipids).
Water-soluble vitamins do not get stored in the body for long - they soon get expelled through urine.
Water-soluble vitamins need to be replaced more often than fat-soluble ones.
Vitamins A, D, E and K are fat-soluble.
Vitamins C and all the B vitamins are water-soluble.2
List of vitamins
Let's take a look at the different types of vitamins.
Carrots are a good source of vitamins A and B3
- Chemical names (vitaminer) - retinol, retinal, and four carotenoids (including beta carotene).
- Fat soluble
- Deficiency may cause night-blindness and keratomalacia (eye disorder that results in a dry cornea)
- Good sources include: liver, cod liver oil, carrots, broccoli, sweet potato, butter, kale, spinach, pumpkin, collard greens, some cheeses, egg, apricot, cantaloupe melon, milk.
More information is available in our Vitamin A article.
- Chemical name (vitaminer) - thiamine
- Water soluble
- Deficiency may cause beriberi, Wernicke-Korsakoffsyndrome
- Good sources include: yeast, pork, cereal grains, sunflower seeds, brown rice, whole grain rye, asparagus, kale, cauliflower, potatoes, oranges, liver, and eggs.
More information is available in our Vitamin B article.
- Chemical name (vitaminer) - riboflavin
- Water soluble
- Deficiency may cause ariboflavinosis
- Good sources include: asparagus, bananas, persimmons, okra, chard, cottage cheese, milk, yogurt, meat, eggs, fish, and green beans.
Broccoli belongs to the cruciferous vegetable family and is a good source of vitamins A, B3 and B5.
- Chemical names (vitaminer) - niacin, niacinamide
- Water soluble
- Deficiency may cause pellagra
- Good sources include: liver, heart, kidney, chicken, beef, fish (tuna, salmon), milk, eggs, avocados, dates, tomatoes, leafy vegetables, broccoli, carrots, sweet potatoes, asparagus, nuts, whole grains, legumes, mushrooms, and brewer's yeast.
More information is available in our Vitamin B3 article.
On the next page we look at vitamins B5, B6, B7, B9, B12, C, D, E and K. We also feature a video discussing the different types of vitamins.