Ingredient upper-limit guides

Choose an ingredient to review its existing reference guide. These pages describe cited references and evidence boundaries; they do not determine whether your personal dose is safe.

• Vitamin A
• Vitamin D
• Iron
• Selenium
• Calcium
• Zinc
• Magnesium
• Vitamin B6
• Niacin
• Vitamin E
• Iodine
• Copper
• Vitamin K