Why Choose BritVits Vitamin B2?. Vitamin B2 (Riboflavin) 150mg Tablets – High Strength Daily Support. High Strength 150mg Riboflavin Per Tablet. Vitamin B2 (Riboflavin) 150mg 10714%. Vitamin B2 (Riboflavin) is a water-soluble vitamin that contributes to several important functions in the body, including.