A A A « Diseases/Conditions Vitamin and Calcium Supplements Vitamin D Slideshow Vitamins Quiz Page 0 of 13 Table of Contents What are vitamins, and why are they important? Calcium Vitamin D Folic acid Vitamin E Vitamin A Vitamin C Vitamin B12 Vitamin B6 Thiamin (vitamin B1) Niacin Riboflavin Vitamin K Page 0 of 13 What are vitamins, and why are they important? Calcium Vitamin D Folic acid Vitamin E Vitamin A Vitamin C Vitamin B12 Vitamin B6 Thiamin (vitamin B1) Niacin Riboflavin Vitamin K Close TOC