What does Vitamin C Effervescent do? Effervescent tablets allow fast absorption of Vitamin C into the blood stream. ... Vitamin C also contributes to normal collagen formation for the function of blood vessels, bones, cartilage, gums, teeth and skin. It also contributes to the functioning of our immune system as our immune systems can sometimes weaken, without us even being aware of it. Often our bodies are fighting something detrimental to our health, we may feel fatigued or exhausted for no apparent reason. Stress and physical activity additionally wear out our organism, and our immunity is in need of some reinforcement. Vitamin C contributes to normal immune function, and aids it in the everyday struggle against fatigue and tiredness.