I take a Vitamin C supplement and make sure we get plenty of Vitamin C from food to support our immune systems, using easy + delicious recipes like these! (gfreefoodie.com)
In a pinch, you could also get plenty of Vitamin D from a full - spectrum lamp. (healthybrainforlife.com)
Plus, grapes contain plenty of vitamin C and others that are essential for improving health! (jaylabpro.com)