This time on Vitamin ABCs, dive into two supplements with big benefits. Hyaluronic acid isn't just for skincare. Taking 80-200 mg of this supplement for at least two months has been shown to improve joint function and reduce knee pain from osteoarthritis — especially for people 40-70 years old. Plus, have you heard of n-acetyl cysteine? Now you have! It can help thin the mucus in your airways for easier breathing (among other health perks).