Whether you take an over-the-counter tablet or have been used to drinking fresh orange juice every day as a child, we've been giving our bodies Vitamin C in one form or the other. However, your skin needs a little extra. Vitamin C is an anti-oxidant that boosts collagen production in the skin, increasing its elasticity and making your skin look glowy and youthful. It has anti-inflammatory properties and also helps to even out your skin tone and minimise sun damage, not as much as your SPF though - don't ignore your SPF.
Use a few drops all over your face in the morning before your moisturiser and SPF.