What are vitamins?
Vitamins are essential for our bodies’ biological processes. Each vitamin has specific roles in the body and we need them to maintain our overall health. Vitamins are micronutrients – meaning that we need them in relatively smaller quantities than macronutrients (carbohydrates, proteins and lipids).
Our bodies cannot synthesize vitamins and so they must be supplied from our diets. Vitamins are important to maintain healthy bones and muscle tissue, support our immune system, and ensure healthy vision.
There are two classes of vitamins:
These vitamins are stored in the human body and so toxicity can occur from consuming an excess amount. If consumed in large amounts, toxicity symptoms include damage to our hair, bone, eyes, skin, and nervous system. These vitamins are: A, D, E, and K. They can be found in a variety of fat-containing foods such as meats, dairy products, avocados, nuts, and seeds.
These vitamins and not stored in the human body as excess is excreted in urine. Toxicity generally occurs as a result of vitamin supplementation. These vitamins are: C, B vitamins (thiamin, riboflavin, niacin, vitamin B6, vitamin B12, pantothenic acid, biotin, and folate). Because we cannot store these vitamins, toxicity rarely occurs. These vitamins are abundant in many foods such as whole grains, fruits, vegetables, meat, and dairy products.
Some vitamins and their functions
|Vitamin||Some food sources||Function|
|Vitamin B1||Whole grains, dried beans, nuts and seeds||Helps with energy production in your body|
|Vitamin B12||Milk, cheese, yogurt, meat, fish, poultry, eggs, fortified soy products||Helps make healthy blood cells.
Low level of this vitamin can cause anemia.
It keeps nerves working properly.
|Vitamin C||Citrus fruits (oranges, grapefruits), kiwi, strawberries, mangoes, papaya, peppers, broccoli and more||Helps heal cuts and wounds.
Keeps gums healthy.
Protects from infections by keeping your immune system healthy.
Increases the amount of iron your body absorbs from some foods.
|Vitamin A||Liver, some fish, milk, cheese||Helps you to see in the day and at night. Promotes normal growth.
Protects from infections by keeping skin and other body parts healthy.
Most people can get enough vitamins by eating a variety of healthy foods from the four major food groups (meats and alternatives, dairy products and alternatives, vegetables and fruits, and grains).
Stephanie Aboueid, RD
Nutrition: A functional approach by Judy Sheeshka, Pearson Education Canada; 2 edition.