Vitamins and Supplements: Types, Uses, Quality, and Safety
Vitamins and other dietary supplements are products some people take to fill a nutritional gap or to meet a specific need.
They may be used if someone's diet is restricted or if a health professional recommends them for a particular situation.
But you don't automatically need supplements, and how useful they are depends on the product, what you want it for, and who is taking it.
When it comes to supplements, what works for one person will not work for another. “Natural” doesn't always mean safe, as products can also have side effects or interact with medications.This manual will walk you through the most common types of supplements, how to assess a product's quality, and ways to consider safety. This is for educational purposes and is not health advice for your situation.
What is a dietary supplement?
“Dietary supplements” are products intended to supplement (add further nutritional value to) the diet of a person.They may contain vitamins, minerals, herbs or other botanicals, amino acids, or other substances. Some products have one ingredient; some have a mix of ingredients.
Supplements come in many forms, such as pills, capsules, powders, liquids, and gummies. They are not like normal foods, which you eat as part of meals or snacks, or medicines, which you use to diagnose, treat, or prevent health conditions.
Supplements come in many forms, such as pills, capsules, powders, liquids, and gummies. They are not like normal foods, which you eat as part of meals or snacks, or medicines, which you use to diagnose, treat, or prevent health conditions.
These categories can be confusing at times, especially if a product is being marketed for a health benefit.
The way a supplement is packaged or marketed doesn't tell you if it's the right or effective choice for a specific person. Check the product contents and ask for qualified advice if you are unsure whether it is suitable for you.
Vitamins: Products that contain one or more vitamins, such as vitamin C or vitamin D.
Minerals: Things that have minerals in them, like iron, calcium, or magnesium.
Multivitamins: A mixture of several vitamins, sometimes with minerals. Formulas and amounts can vary.
Omega-3 products: Products that contain omega-3 fatty acids, sometimes from fish oil or other sources.
Probiotics: Products containing live microorganisms. Types and amounts can vary.
Protein powders: Powders made from protein sources, like dairy or plants; some have other ingredients.
Herbal or botanical products: Products that are made from plants or parts of plants such as leaves, roots, or extracts. The ingredients and their preparation are different.
These categories describe what products can have, not what they will do. How well it works and how appropriate it is depends on the product itself, what it contains, and who is using it.
1. Read the label. Find the active ingredients, amount per serving, serving size, and other ingredients on the Supplement Facts or similar panel.
2. Check the dosage. Check with a qualified professional for advice. Beware of vague, exaggerated, or disease-treating claims.
3. Seek independent quality testing. Where available, credible third-party testing or certification can help check identity, purity, or manufacturing quality. It does not prove a product is effective or risk-free.
4. Compare formulas. Ingredients in combo products, proprietary blends, and multiple supplements can be duplicated. Add the total amount you would take from all sources.
5. Check the product. Check expiration dates, follow storage instructions, and avoid products with damaged or unsealed packaging.
Types of supplements you might see
Supplements can be made with different ingredients for different purposes. Common categories are:Vitamins: Products that contain one or more vitamins, such as vitamin C or vitamin D.
Minerals: Things that have minerals in them, like iron, calcium, or magnesium.
Multivitamins: A mixture of several vitamins, sometimes with minerals. Formulas and amounts can vary.
Omega-3 products: Products that contain omega-3 fatty acids, sometimes from fish oil or other sources.
Probiotics: Products containing live microorganisms. Types and amounts can vary.
Protein powders: Powders made from protein sources, like dairy or plants; some have other ingredients.
Herbal or botanical products: Products that are made from plants or parts of plants such as leaves, roots, or extracts. The ingredients and their preparation are different.
These categories describe what products can have, not what they will do. How well it works and how appropriate it is depends on the product itself, what it contains, and who is using it.
Selecting Quality Vitamins and Supplements
First, understand why you’re looking at a product—and whether you need a supplement at all. Here are the procedures for comparing options:1. Read the label. Find the active ingredients, amount per serving, serving size, and other ingredients on the Supplement Facts or similar panel.
2. Check the dosage. Check with a qualified professional for advice. Beware of vague, exaggerated, or disease-treating claims.
3. Seek independent quality testing. Where available, credible third-party testing or certification can help check identity, purity, or manufacturing quality. It does not prove a product is effective or risk-free.
4. Compare formulas. Ingredients in combo products, proprietary blends, and multiple supplements can be duplicated. Add the total amount you would take from all sources.
5. Check the product. Check expiration dates, follow storage instructions, and avoid products with damaged or unsealed packaging.
Why people use them.
People take supplements for many reasons. Some want to meet a nutrient need identified through a health professional's assessment.Some people may eat a limited diet or have trouble getting certain nutrients from the foods they normally eat. It may also be recommended as part of advice for a particular health condition.
Such reasons do not mean that a supplement is needed or useful in all cases. There is mixed evidence for individual ingredients and for each use. Whether a product is right for a person depends on their diet, health and medicines.
Such reasons do not mean that a supplement is needed or useful in all cases. There is mixed evidence for individual ingredients and for each use. Whether a product is right for a person depends on their diet, health and medicines.
Products in the same category may vary in the ingredients they contain and the amounts of those ingredients.
If you are considering taking a supplement to address a health issue or potential nutrient deficiency, a health professional can help you determine whether it is right for you and discuss other options.
A supplement may be worth considering when a person’s diet is restricted, a nutrient need has been identified, or a health professional recommends one for a specific situation.
First, food; supplements when required
A varied eating pattern provides many vitamins and minerals, as well as protein, fiber, and other nutrients. Eating a variety of foods can help you get a range of nutrients over time. But eating well does not always work for everyone.A supplement may be worth considering when a person’s diet is restricted, a nutrient need has been identified, or a health professional recommends one for a specific situation.
The right choice depends on what a person eats, their health needs, and any medicines they are taking. Food is not always sufficient for every individual, and supplements are not necessarily better or required.
If you’re unsure whether a supplement may be helpful, discuss your diet and circumstances with a qualified health professional. They can help you think through whether a product is appropriate and how it fits in with your overall care.
Active Ingredients: The vitamins, minerals, and other materials contained in the product.
Amount of each active ingredient per serving.
Serving size: how many pills or scoops are in a serving.
Directions: Products may vary. Read directions on product/package before use.
Expiry date.
Other ingredients such as flavorings or fillers and if they matter to you.
It can provide information on whether a product is as labeled and meets certain standards, based on independent quality testing.
If you’re unsure whether a supplement may be helpful, discuss your diet and circumstances with a qualified health professional. They can help you think through whether a product is appropriate and how it fits in with your overall care.
How to measure product quality?
Before you buy a supplement, read the label so you know what the product is and how it is supposed to be used. Check:Active Ingredients: The vitamins, minerals, and other materials contained in the product.
Amount of each active ingredient per serving.
Serving size: how many pills or scoops are in a serving.
Directions: Products may vary. Read directions on product/package before use.
Expiry date.
Other ingredients such as flavorings or fillers and if they matter to you.
It can provide information on whether a product is as labeled and meets certain standards, based on independent quality testing.
That doesn’t prove the product works or is safe for all people. Quality information is only part of the decision; ingredients, intended use, and your circumstances matter, too.
If you are unsure how to use a label or whether a product is right for you, please consult a qualified health professional or your pharmacist.
Side effects and interactions Safety
Supplements can cause side effects and may interact with prescription and non-prescription medicines or other supplements.The effects can vary depending on the product and on you, so don't assume a product is harmless just because it is labeled natural or sold without a prescription.
Do not take more than the label recommends. Follow the directions on the label. Talk to a health professional or a pharmacist before taking any supplements, especially if you take medication or are managing a health condition.
Do not take more than the label recommends. Follow the directions on the label. Talk to a health professional or a pharmacist before taking any supplements, especially if you take medication or are managing a health condition.
They can help you review the ingredients and consider whether the product could interact with your medicines or affect your care. If you already take a few supplements, tell us about those too.
If you notice any undesirable effect after taking a supplement, consult a health professional for guidance. Have the product label accessible to share ingredients and directions.
If you notice any undesirable effect after taking a supplement, consult a health professional for guidance. Have the product label accessible to share ingredients and directions.
Before using any supplement, seeking advice can help you make a more informed decision, rather than assuming it is necessary or suitable for everyone.
Pregnant or breastfeeding people should ask a health professional if a product is right for them.
Children may have different nutritional needs than adults, and you should check with a qualified professional before giving them a supplement.
Older adults may be taking medications or managing health conditions that are relevant for supplement use. A professional can help evaluate possible interactions.
If you are going to have surgery, let your care team know about any supplements you take and ask if you should keep taking them.
People with ongoing health issues should speak to a health professional about a supplement, especially if they are taking medication or undergoing ongoing treatment.
If any of these happen, show the product label and a list of medicines and other supplements to the professional you consult. “Don’t go off and build a product based on generic advice or marketing speak.
Look at the label. Look at the active ingredients, the amount per serving, the serving size, and the directions.
Check for possible interactions. Talk to your health care professional or pharmacist if this product may interact with your medicines or other supplements.
Seek credible quality information. Independent testing can tell you about the accuracy of labels and some standards, but it doesn’t prove a product works or is right for you.
Talk about a question. If you do not know what it is or if it is right for you, post the label here and ask before taking it.
Beware of products promising guaranteed results or claiming to fix a wide range of problems. Think about whether the claims are realistic and whether the supplement is right for you.
Supplements are suitable for people who need them, but they are not automatically necessary, safe, or effective.
The most careful should be:
Some people should speak to their doctor before taking a supplement. A health professional or pharmacist can review the product, as well as a person’s health needs and other care.Pregnant or breastfeeding people should ask a health professional if a product is right for them.
Children may have different nutritional needs than adults, and you should check with a qualified professional before giving them a supplement.
Older adults may be taking medications or managing health conditions that are relevant for supplement use. A professional can help evaluate possible interactions.
If you are going to have surgery, let your care team know about any supplements you take and ask if you should keep taking them.
People with ongoing health issues should speak to a health professional about a supplement, especially if they are taking medication or undergoing ongoing treatment.
If any of these happen, show the product label and a list of medicines and other supplements to the professional you consult. “Don’t go off and build a product based on generic advice or marketing speak.
A practical checklist before you purchase
State your reason. Be specific about the need or concern you hope the supplement will address.Look at the label. Look at the active ingredients, the amount per serving, the serving size, and the directions.
Check for possible interactions. Talk to your health care professional or pharmacist if this product may interact with your medicines or other supplements.
Seek credible quality information. Independent testing can tell you about the accuracy of labels and some standards, but it doesn’t prove a product works or is right for you.
Talk about a question. If you do not know what it is or if it is right for you, post the label here and ask before taking it.
Beware of products promising guaranteed results or claiming to fix a wide range of problems. Think about whether the claims are realistic and whether the supplement is right for you.
Supplements are suitable for people who need them, but they are not automatically necessary, safe, or effective.
Consider why you want to use a product, check the ingredients, and ask a qualified health professional or pharmacist if you are unsure.
An informed choice is based on your own situation, not on vague promises or the idea that one product fits all.
When to Seek Professional Help
If you have a health condition, take medicines, or are unsure whether you have a deficiency, speak to a doctor, pharmacist, or registered dietitian before starting supplements.Don’t self-diagnose or take supplements in place of an evaluation, and seek professional advice for persistent symptoms.
A clinician may consider your diet, symptoms, medical history, and appropriate tests before recommending a supplement.
A clinician may consider your diet, symptoms, medical history, and appropriate tests before recommending a supplement.
Bring or share the product's name, label, dose, and frequency so they can evaluate the ingredients and potential interactions.
For practical help, visit official health-system or professional-association websites to locate qualified care.
For practical help, visit official health-system or professional-association websites to locate qualified care.
For example, the American Osteopathic Association (AOA) and the American Medical Association (AMA) have information about their organizations and how to find physicians.
Check the organization’s official website to confirm the contact details and do not use an address or phone number from an advertisement or search result that is not verified.
Check the organization’s official website to confirm the contact details and do not use an address or phone number from an advertisement or search result that is not verified.
If you’re using an organization’s app, find it on the organization’s official website or on the Apple App Store.
If the organization has an app store scan QR code option, follow the organization’s instructions and check the publisher before downloading.
The practical takeaway: Have a good reason to take a vitamin or supplement, prioritize food first, check the quality of what you're buying, and use supplements safely with professional guidance when needed.
The practical takeaway: Have a good reason to take a vitamin or supplement, prioritize food first, check the quality of what you're buying, and use supplements safely with professional guidance when needed.
