Vitamin - Wikipedia
Vitamin | Definition, Types, & Facts | Britannica
Vitamins and Minerals From A to Z - WebMD
What Are Vitamins? - Healthline
What are vitamins, and how do they work? - Medical News Today
Vitamins: MedlinePlus Medical Encyclopedia
What Are Vitamins, and Why Are They Important? - Verywell Health
Vitamins - MedlinePlus
Vitamins and Minerals – The Nutrition Source
Vitamin and Mineral Supplement Fact Sheets - Office of Dietary ...