Posted by Kristina Mullahoo, DtP, MSc on March 31, 2021
Kristina Mullahoo, DtP, MSc

Dietitians often get asked if they need to take a supplement to prevent certain diseases or improve their health. Someone can be in their peak health, but the minute you remind them that they need vitamin C, it can kick start a bout of anxiety and doubt. 

Those concerns are completely understandable. But keep in mind, getting your body’s fill of vitamins will just happen naturally, provided you manage to mix up your diet with a variety of foods like those suggested in Canada’s Food Guide. These include colorful veggies, fruits, whole grains, protein foods like meat, poultry, legumes, nuts, dairy, fish.



What are vitamins?

Vitamins, along with minerals, are considered micronutrients and are needed in small amounts to help our bodies perform essential functions to maintain health and life. We do not create them ourselves, so we need to get them from outside sources. Too little or too much of these nutrients can lead to health problems. 

Vitamins can be split into 2 categories: fat-soluble and water-soluble


Fat-soluble vitamins:

  • Vitamins A, D, E and K
  • Stored in our bodies for a period of time and require fats to help in their absorption
  • Typically you can go a few weeks without needing to replenish them


Water-soluble vitamins:

  • Vitamins C and B, where B vitamins comprise of 8 different types
  • Excreted in our urine and not stored in our bodies
  • We need to consume them every 1-3 days to avoid deficiency 


The following table is a guide that can help you determine which foods to get these vitamins from and why they are needed (it is not at all exhaustive).



Food sources

Main functions in the body

Vitamin C

Citrus fruits, bell peppers, broccoli, brussels sprouts, cauliflower, cantaloupe, strawberries, tomatoes, papaya, mango, kiwi

Collagen synthesis (strengthens tissues), antioxidant, amino acid metabolism, helps with iron absorption and resistance to infection

Thiamin (B1)

Whole grains or enriched grain products, squash, soy milk, pork – found in many other foods

Energy metabolism

Riboflavin (B2)

Milk products, whole grains or enriched grain products, liver

Energy metabolism

Niacin (B3)

All protein foods (meat, fish, dairy, nuts, eggs), whole grains or enriched grain products

Energy metabolism

Pantothenic acid (B5)

Chicken, beef, potatoes, oats, whole grains, broccoli, liver, egg yolk – found in many other foods

Energy metabolism

Pyridoxine (B6)

Meat, fish, poultry, potatoes, legumes, banana, melon

Making of red blood cells, amino acid and fatty acid metabolism

Biotin (B7)

Liver, egg yolks, soybeans, fish, whole grains – found in many other foods

Energy and amino acid metabolism, fat and glycogen synthesis

Folate (B9)

Fortified grains, leafy green vegetables, legumes, seeds, liver

DNA synthesis / new cell formation

Cobalamin (B12)

Animal based foods (meat, poultry, fish & seafood, dairy, eggs), fortified cereals, nutritional yeast

New cell synthesis, maintains nerve cells, aid in breakdown of some fatty acids and amino acids

Vitamin A

Liver, sweet potatoes, carrots, fortified dairy products, dark leafy greens

Helps with vision functions, bone and tooth growth, reproduction and immunity

Vitamin D

Fortified dairy and alternatives, liver, fatty fish like salmon and trout, eggs

*made in the body when skin is exposed to sunlight – but not from October to April for people living in Canada due to angle of the sun. 

Increases calcium absorption, aids in immune function, keeps bones, teeth and muscles healthy

Vitamin E

Leafy greens, plant based oils, whole grains, nuts & seeds, egg yolk


Vitamin K

Leafy greens, cabbage-type vegetables, milk, liver

Helps to make blood-clotting and bone proteins



Fun facts about vitamins

  • Some vitamins, like vitamin C, folate, vitamin B6, and thiamin are easily destroyed by heat, so having some uncooked or frozen versions of these nutrient-containing foods is ideal. And yes, frozen is just as nourishing as fresh!
  • They are also better absorbed and will supply you with more nutrients like fiber, carbohydrates, protein, fat and other micronutrients when they come from real food instead of a concentrated supplement
  • Water-soluble vitamins (B’s and C) will be excreted in your urine once your body gets what it needs – so taking supplements containing these vitamins will likely just wind up down the toilet!



Is a supplement actually needed? 

The simple answer: nope! We can get the majority of our vitamins from real food. Seek to tweak and optimize your eating habits first, then determine if there is a need for a supplement. Be sure to ask a dietitian or your health care provider if you would like more guidance on whether or not a supplement is right for you**, but don’t be surprised if they send you home with a prescription paper that looks an awful lot like a grocery list for a farmer’s market.


If you have more questions about vitamins and minerals, check out this link from the Dietitians of Canada. 


*Use of sunscreen, clothing, staying indoors, darker skin tone, age, smog can also limit sun exposure and vitamin D synthesis in the warmer months, whereby a supplement may be needed for those unable to get it from food. A daily supplement of 400-1000 IU/d is considered safe. Health Canada recommends all Canadians over 50 y.o. to take a vitamin D supplement of 400 IU/d.

**Some groups of people like women who plan on getting pregnant, or are pregnant/breastfeeding, people over the age of 50, those who have certain medical conditions or food intolerances, and those who follow a restrictive diet may require additional supplements to meet their needs.



Topics: Health and Wellness