Vitamins are essential parts of the food for your body which can be obtained by maintaining healthy diet habits. The body goes through thousands of chemical reactions every day to do various functions such as producing skin, bone etc and to do all this, the body requires some raw materials. These include several vitamins, minerals, and dietary components which can not be manufactured on its own in required amounts.
The vitamins which you can not find in foods:
1) for pregnant women, need folic acid,  iron and/or vitamin D supplements as medically advised
2) for vegans, may need a B12 supplement, supplements containing Vitamin D, Omega-3 fatty acids and iron as prescribed or medically advised
Supplements may pose health problems. High doses of vitamin C may lead to diarrhoea and kidney stones. Excess of vitamin A is harmful, especially for pregnant women. You should always be careful with doses of vitamins and minerals.
Here’s a list of all the important vitamins which help in respective body mechanisms.
Vitamin A:  Growth, eyesight, immune system and defence against infections. Sources- Full cream dairy products, Liver and fish oil, Orange coloured fruits and vegetables, Meat, eggs
Vitamin B1 (thiamin): Processing carbohydrates to energy, healthy working of your heart, digestive system, nervous system, control of cholesterol. Sources – Pork, wholemeal bread, oats, yeast extract, fortified breakfast cereals, seeds, fish, nuts
Vitamin B2 (riboflavin): helps in tissue growth and repair including skin and eyes. Sources – leafy green vegetables, milk and milk products, meat, enriched bread and breakfast cereals
Vitamin B3 (niacin): helps in processing foods to energy, assists to improve nervous system, skin health and digestive system. Sources – fish, meat, poultry, mushrooms, asparagus, and leafy green vegetables, peanuts, enriched bread and breakfast cereals.
Vitamin B5 (pantothenic acid): helps in processing foods to energy. Sources- beef, Organ meats (liver, kidney), Chicken breast, Avocado Mushrooms, Nuts, seeds, Yogurt, Dairy milk, Potatoes
Vitamin B6 (pyridoxine): helps in making red blood cells, processing proteins and carbohydrates, brain function, nerves and muscles, immune system. Sources- fish, meat, poultry, fruits, vegetables.
Vitamin B12: helps in formation of new red blood cells, new nerve cells and processing fats and carbohydrates. Sources- fish, meat, eggs, poultry, dairy products.
Folate (vitamin B9): helps in the formation of new red blood cells, healthy nervous system and nervous system development during pregnancy. Sources – liver, green leafy vegetables, legumes, oranges, seeds, bread, breakfast cereals
Vitamin C: antioxidant, boost the immune system, metabolise protein, help absorb iron. Sources- citrus fruits, cantaloupe, vegetables in the cabbage family, strawberries, tomatoes, capsicum, potatoes, mangoes, paw paw, kiwifruit
Vitamin D: for healthy bones and teeth, required to metabolise calcium and for many organs including the liver, intestine, and kidneys. Sources – sunrays to exposed skin, herrings and sardines, salmon, fortified milk and margarine, egg yolks
Vitamin E: an antioxidant, keeps the membranes around cells healthy. Sources – liver,  sunflower oil and safflower oil, nuts and seeds, leafy green vegetables, wholegrain products, wheat germ, egg yolks
Vitamin K: helps to make various proteins required for blood clotting and the building of bones. Sources – milk, leafy green vegetables, members of the cabbage family.