My skin has been looking dull lately, so I'm looking into health functional foods.

Yesterday, I met up with some friends for the first time in a while to take pictures, and I was shocked to see my skin under the warm white lights. I thought I was taking good care of it, but my makeup was all over the place and my complexion was so dark. My friend next to me said she'd been working all night but still looked so vibrant, so I asked her what her secret was. She said she's already been taking care of it. I'm thinking about learning more about health functional foods that replenish the skin from the inside out, not just the surface. I thought only parents took these, but seeing all my friends and coworkers carrying one in their bags makes me anxious and wonder if I'm too late. With so many different ingredients, I'm not sure which ones I should start with to get the best results. If you had to choose just one health functional food to take specifically to manage your skin, what would it be? Since this is my first time, I think something easy to swallow or tasty would be ideal. If you have any recommendations for health functional foods that I can take consistently every day, please let me know. I'm really curious to know how you all manage your skin concerns during the seasonal transition!