Understanding Micronutrients: Vitamins
What are vitamins?
Vitamins are organic compounds that the human body needs in small amounts to function properly.
Unlike macronutrients (proteins, carbohydrates, and fats), vitamins don't give us energy directly. Instead, they serve as crucial helpers in countless processes that are happening in the body. You can think of them as tiny molecular workers that keep your body running smoothly by performing specific jobs, from supporting your immune system to helping your blood clot properly.
Why do we need them?
Vitamins are absolutely essential for normal cell function, growth, and development. Aside from supporting your immune system, some of their critical jobs are:
- Helping your body convert food into energy
- Repairing cellular damage
- Aiding in the formation of bones, tissues, and blood cells
- Protecting cells from oxidative damage
Without adequate vitamin intake, your body begins to malfunction. Vitamin deficiencies can lead to various health problems, from scurvy (vitamin C deficiency) to rickets (vitamin D deficiency), and many other conditions that were once common but are now rare in developed countries thanks to improved nutrition.
Do they give us energy?
This is one of the most common misconceptions about vitamins. Despite what some supplement labels might suggest, vitamins themselves don't provide energy in the form of calories.
What vitamins actually do is help your body convert the food you eat (carbohydrates, proteins, and fats) into usable energy. You can think of them as facilitators rather than fuel.
So while taking a vitamin supplement won't give you an immediate energy boost like a cup of coffee might, maintaining proper vitamin levels will help you make sure that your body can efficiently produce the energy it needs from the food you consume.
Where do we get them from?
The best sources of vitamins are whole, unprocessed foods. Here's a general guide:
- Fruits and vegetables are excellent sources of vitamins A, C, and several B vitamins.
- Whole grains provide many B vitamins.
- Nuts and seeds contain vitamin E and some B vitamins.
- Animal products like meat, eggs, and dairy are especially important for vitamin B12.
- Fatty fish, egg yolks, and sun exposure help with vitamin D.
While a balanced diet should ideally provide all the vitamins you need, certain situations may call for supplementation – like during pregnancy, for specific health conditions, or for those with restricted diets. You'll always want to consult with a healthcare provider before starting supplements.
Vitamins and cooking
It's important to know that vitamins can be delicate. Some are easily destroyed during food preparation and cooking. For example:
- Water-soluble vitamins (like vitamin C and B vitamins) can leach into cooking water.
- Heat can break down certain vitamins.
- Exposure to air can oxidize and degrade some vitamins.
- Light can destroy vitamin content in stored foods.
To minimize loss of vitamins, try these strategies:
- Store fruits and vegetables properly.
- Cut produce just before using.
- Steam or microwave vegetables instead of boiling.
- Cook for the minimum time necessary.
- Use the cooking liquid in soups or sauces when possible.
Fat-soluble vs. water-soluble vitamins
Vitamins fall into two major categories that affect how they behave in your body:
Fat-soluble vitamins (A, D, E, and K):
- Dissolve in fat
- Can be stored in your liver and fatty tissues
- Don't need to be consumed daily
- Are better absorbed when eaten with some fat
- Can potentially build up to toxic levels if consumed in excess
Water-soluble vitamins (C and all B vitamins):
- Dissolve in water
- Are not stored in significant amounts (except B12)
- Need to be consumed more regularly
- Excess amounts are typically excreted in urine
- Are less likely to reach toxic levels
Understanding this distinction helps explain why some vitamins need to be consumed regularly while others can be taken less frequently, and why some supplements should be taken with food while others can be taken any time.
In practice
A well-balanced diet rich in fruits, vegetables, whole grains, lean proteins, and healthy fats is your best strategy for getting all the vitamins your body needs.
Supplements can help fill gaps, but they can't replace the complex matrix of nutrients found in whole foods.
If you'd like to learn more
... check out these sources:
- Definition of vitamins as organic compounds needed in small amounts: National Institutes of Health, Office of Dietary Supplements. "Vitamin and Mineral Supplement Fact Sheets." https://ods.od.nih.gov/factsheets/list-VitaminsMinerals/
- 13 essential vitamins and their classifications: Harvard T.H. Chan School of Public Health. "Vitamins." https://www.hsph.harvard.edu/nutritionsource/vitamins/
- Vitamins' roles in cell function, growth, and development: U.S. National Library of Medicine, MedlinePlus. "Vitamins." https://medlineplus.gov/vitamins.html
- Vitamin deficiency diseases (scurvy, rickets): World Health Organization. "Micronutrient Deficiencies." https://www.who.int/nutrition/topics/micronutrients/en/
- Vitamins' role in energy metabolism: Academy of Nutrition and Dietetics. "How Vitamins and Minerals Work in the Body." https://www.eatright.org/food/vitamins-and-supplements/types-of-vitamins-and-nutrients/how-vitamins-and-minerals-work-in-the-body
- B vitamins as cofactors in energy production: Linus Pauling Institute, Oregon State University. "B Vitamins." https://lpi.oregonstate.edu/mic/vitamins/vitamin-B
- Food sources of various vitamins: USDA FoodData Central. https://fdc.nal.usda.gov/
- Effects of cooking methods on vitamin retention: Journal of Food Science and Technology. "Effect of different cooking methods on nutritional value of vegetables." https://www.springer.com/journal/13197
- Fat-soluble vs. water-soluble vitamins properties: Centers for Disease Control and Prevention. "Vitamins and Minerals." https://www.cdc.gov/nutrition/micronutrient-malnutrition/micronutrients/index.html
- Potential toxicity of excess fat-soluble vitamins: Mayo Clinic. "Vitamin toxicity: Can vitamins be harmful?" https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/expert-answers/vitamin-overdose/faq-20058030
- Storage and excretion of water-soluble vitamins: British Nutrition Foundation. "Vitamins." https://www.nutrition.org.uk/nutritionscience/nutrients-food-and-ingredients/vitamins.html