Principle Immune Boost+ Effervescent Tablets: Comprehensive Immune Support in a Tasty Drink. ‣ Formulated with essential vitamins and minerals for immune health. ‣ Effervescent tablets for better absorption. ‣ Convenient and easy to take. SUGGESTED USE: Dissolve one tablet in a glass of water daily, or as directed by your healthcare provider. INGREDIENTS: Vitamin C, Vitamin D, Zinc, Citric Acid, Sodium Bicarbonate, Natural Flavors, Sweeteners.