Can I use vitamin c 20% with hyaluronic acid after microneedling?

I would refrain from using any products (such as a topical vitamin c) that could cause adverse reactions, irritation or unwanted inflammation immediately after microneedling.  For the first day or two after microneedling, I would recommend a gentle cleanser and a moisturizer.   

We recommend following up with your physician who administered your treatment as they know your skin best. If a vitamin c serum is suggested, clinical studies have demonstrated that SkinCeuticals C E Ferulic serum is well tolerated to be used post microneedling treatment. Follow with SkinCeuticals Phyto Corrective Masque and leave on for 7-10 minutes. Rinse with warm water. Correct your face with SkinCeuticals Phyto Corrective Gel serum and apply 3-5 drops to treated areas. Lastly, wear a broad spectrum sunscreen, like SkinCeuticals Physical Fusion UV Defense to face, neck, and chest. Hope this is helpful.