Important: This page is general information, not medical advice. It does not recommend or prescribe any treatment. Always consult your doctor or pharmacist before starting, stopping or changing any medicine.
About Vitamins
Vitamins are substances that your body needs to grow and develop normally. There are 13 vitamins your body needs. They are:
- Vitamin A
- B vitamins (thiamine, riboflavin, niacin, pantothenic acid, biotin, vitamin B-6, vitamin B-12 and folate)
- Vitamin C
- Vitamin D
- Vitamin E
- Vitamin K
You can usually get all your vitamins from the foods you eat. Your body can also make vitamins D and K. People who eat a vegetarian diet may need to take a vitamin B12 supplement.
Each vitamin has specific jobs. If you have low levels of certain vitamins, you may get health problems. For example, if you don't get enough vitamin C, you could become anemic. Some vitamins may help prevent medical problems. Vitamin A prevents night blindness.
The best way to get enough vitamins is to eat a balanced diet with a variety of foods. In some cases, you may need to take vitamin supplements. It's a good idea to ask your health care provider first. High doses of some vitamins can cause problems.
It sits within Food and Nutrition.
The lead U.S. institute for this subject is the NIH Office of Dietary Supplements.
When to speak to someone. Reading about a topic cannot tell you whether it applies to you. Speak to a doctor or pharmacist if symptoms are severe, sudden, getting worse, or simply not going away — and seek emergency care immediately for chest pain, breathing difficulty, sudden weakness or confusion, or a serious allergic reaction.
Research on Vitamins
4,335 studies areregistered for this condition on ClinicalTrials.gov, the U.S. National Library of Medicine's public registry. A selection is below — the links go straight to the registry entry, not to a summary of ours.
What a registered study does and does not mean. Registration means a study exists and has been declared publicly. It says nothing about whether the treatment being tested works, is safe, or is available to you. Many studies find no benefit — that is what research is for. Never seek out an experimental treatment on the strength of a registry entry alone.
Research currently under way
- Vitamin A Supplementation and Breast Milk Vitamin A Levels in Mothers of Preterm InfantsUniversity of Mississippi Medical Center
- Plasma Lipids-Dependent Vitamin E Metabolism During Dynamic HyperlipidemiaNational Heart, Lung, and Blood Institute (NHLBI)
- Vitamin D and Omega-3 Trial (VITAL)Brigham and Women's Hospital
- Clinical and Laboratory Study of Methylmalonic AcidemiaNational Human Genome Research Institute (NHGRI)
- Vitamin D Status and Asthma Control, Pulmonary Function, and Oxidative Stress in Adults With Bronchial AsthmaSinai University
- B6 Administration for Levetiracetam-Associated Neurobehavioral Changes and EpilepsyDuke University
Research already completed
- The Primary Purpose of This Study is to Determine if Biotin, Vitamin B7 is an Effective Way to Label Platelets in Survival and Recovery Studies.Bloodworks
- The Body's Affect on Vitamin CNational Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
- The Investigation of Vitamin D and Menstrual Cycles Trial, the inVitD Trial: A Phase II Clinical TrialNational Institute of Environmental Health Sciences (NIEHS)
- Effects of Folic Acid and Vitamin E on Hormones in Polycystic Ovary SyndromeAl-Mustansiriyah University
- A Phase 2 Trial of High-dose Ascorbate for Pancreatic Cancer (PACMAN 2.1)University of Iowa
- GLUT-F Improves MASLD Liver FunctionUniversity of Bari
Study data from ClinicalTrials.gov, a service of the U.S. National Library of Medicine. Retrieved 2026-07-30. Registry entries are supplied by study sponsors and investigators; ClinicalTrials.gov does not verify their scientific validity. PocketsInfo is not affiliated with, and not endorsed by, the NLM or the NIH.
Where to read more
Rather than paraphrase, we point you to the primary sources. Every link below is to a government health agency, a national institute or a recognised medical body — grouped by what you are trying to find out.
Start Here
- Dietary Supplement Label Database (DSLD)National Institutes of Health, Office of Dietary Supplements
- Vitamin and Mineral Supplement Fact SheetsNational Institutes of Health, Office of Dietary Supplements
- Vitamins and Minerals: How to Get What You NeedAmerican Academy of Family Physicians
Related Issues
- Can Vitamins Help Prevent a Heart Attack?Mayo Foundation for Medical Education and Research
- Foods for Eye HealthAcademy of Nutrition and Dietetics
- Vitamin Deficiency AnemiaMayo Foundation for Medical Education and Research
Clinical Trials
- ClinicalTrials.gov: MicronutrientsNational Institutes of Health
- ClinicalTrials.gov: VitaminsNational Institutes of Health
Medical subject headings
Clinicians and researchers index this subject under Vitamins, Micronutrients. These are the terms to use when searching medical literature.
This page is built from the MedlinePlus health topic record for Vitamins, a service of the U.S. National Library of Medicine (NLM), National Institutes of Health. Information is from MedlinePlus.gov. PocketsInfo is not affiliated with, and is not endorsed by, the NLM or the NIH. Retrieved 30 July 2026.