Mix of pills (Erich Ferdinand / Flickr)

Generally, eating a balanced diet of healthy foods is the best way to get all of the vitamins you need. So much easier said than done! Dietary restrictions, limited access to affordable, fresh fruits and veggies, poor eating habits and busy schedules get in the way.  

The recommended daily allowance (RDA) of vitamins, minerals and other nutrients are determined by the Institute of Medicine, the health arm of the National Academy of Sciences. They are a non-profit, non-governmental agency comprised of really smart people (such as health care professions, nutritionists, natural, social, and behavioral sciences, among others) who review all of the available data on nutrition, so you don’t have to do it.

SEE ALSO: Seasonal Allergies: How To Help 

Just what are vitamins and minerals?  

Minerals are naturally occurring substances that are critical for cell function and healthy body development. Minerals can be needed in large quantities (macrominerals – think calcium for bones and teeth) or in trace amounts (just a tiny bit – think words that haunted you in high school chemistry such as chromium, molybdenum and zinc).

Vitamins are organic substances that are divided into two main categories, water-soluble and fat-soluble.

Water-soluble vitamins freely distribute throughout the body.  About 60% of an adult body is water. This group includes the B-Complex [thiamin (vitamin B1), riboflavin (vitamin B2), niacin (vitamin B3), pyridoxine (vitamin B6), folate or folic acid (vitamin B12), biotin and pantothenic acid] and Vitamin C (ascorbic acid). These vitamins are cleared by the kidneys and any excess is excreted in urine, meaning they become Vitamin P (cheap shot, couldn’t resist). Consuming too much of a water-soluble vitamin is unusual but can occur with megadoses. Slamming down tons of Vitamin C to fend off a cold can lead to headaches, diarrhea, and cramps – likely worse than cold symptoms.

Fat-soluble vitamins are bound to lipids (fats) in cells. How the body breaks down and uses the fat-soluble group is a slower, more complex process than for their water-soluble colleagues. Vitamins A, D, E and K comprise the fat-soluble group. Excess amounts of these vitamins can accumulate in the body and become toxic.

Supplements are adding vitamins and minerals to your food consumption. Supplements may also contain herbs, botanicals and other substances. The US Food and Drug Administration does not have full regulatory power for over-the-counter supplements. Buyer Beware!

Vitamins and minerals may be used to treat or prevent health conditions. For example, iron is given for anemia, low red blood cells.  Folic acid, Vitamin B12, is important for preventing birth defects of the brain and spinal cord.  These uses are different than taking supplements and are usually under a doctor’s advice.

Each of the 13 letters of vitamin alphabet has a role in building a strong functioning body, that’s why they are called “essential.”  Aim for the RDA!   

So, how do you decide if you need vitamin and mineral supplements?  Most healthy children and adults don’t, but one-third to one-half of individuals take a daily supplement.

Here are a few tips to help you navigate through the supplement aisles and wiles:

1. First and foremost, a balanced diet of a variety of healthy foods generally provides the RDA for vitamins and minerals.

2. Age, health status, food lifestyle (such as vegan) and physical activity determine which vitamins and mineral supplements may be needed.  

a. Growing kids – Consider a daily chewable multivitamin for persistently, finicky eaters, but don’t worry about the occasional missed meal.  Don’t forget the milk (or other dairy) with meals – no bones without it!  Treat vitamins as you would any other medications, including safe storage away from children.

b. Pregnancy and breastfeeding – Definitely a time for supplemental vitamins!  Consuming adequate iron and vitamins for two is difficult.  But, what a great reason for a 3am ice cream splurge?!

c. Adults older than 50 years – Calcium and vitamin D to prevent osteoporosis (weakened bones), especially in women, are important for this group.  As adults age, their metabolism and absorption of nutrients tend to decline. Add on a daily multivitamin to pick up all of the essentials (yes, there are even gummy chewables for adults – thanks Flintstones!)

d. Vegetarian and Vegans – Getting the RDA for vitamins, minerals and other nutrients is challenging for plant-based diets. B12 is found in animal-based foods, eggs and milk, so B12 supplements are generally needed to maintain good health. Consult with a nutritionist to learn tricks for food combinations to optimize nutrients.  Daily supplements may be needed.

e. Athletes – Gobbling up adequate calories, as well as water and electrolytes, to match your level of activity may determine “the thrill of victory or the agony of defeat.”  Exercise can lead to increased losses of vitamins and minerals, so supplements may be beneficial.  This is especially true for athletes following weight-restriction or unbalanced diets.  

3. For most adults, taking an over-the-counter multivitamin poses few risks, though it may not offer much benefit.  As with any medication, consult with your healthcare professional before starting supplements, especially in megadoses.

A few resources for you:

1. http://greatist.com/health/ultimate-guide-vitamins-and-minerals 

2. http://ods.od.nih.gov/Health_Information/ODS_Frequently_Asked_Questions....

3. http://www.healthychildren.org/English/ages-stages/gradeschool/nutrition...

4. http://www.livestrong.com/article/549254-multivitamins-vs-single-vitamins/   

5. http://www.emedicinehealth.com/vitamins_their_functions_and_sources-heal...

6. http://www.medscape.com/viewarticle/717046_8 

7. http://www.jissn.com/content/1/2/1 

Reach Contributor ChrisAnna Mink MD here. Follow the Science Desk here.