Hi sir, I'm 25 years old. I had 8-12 grey hair strands in aug 2022 so I checked my vitamins B12 & D. They were in deficits. So I took over the counter multivitamins for a couple of months  then i stopped taking it. B12 - 208 (Reference Range 211-911) Vit D - 16 (reference range 20-40) Iron - 55 These were the results of the tests. In aug 2023 I started seeing more grey hairs like around 20- 35. I again checked my vitamins levels, the results are - B12 - 200 Vit D - 13 Iron - 76 I'm very much worried about these grey hairs. I don't know what to do now. Can you please suggest what my course of action should be !? I don't think it is genetic bcuz no one had grey hairs at 25 years old in my family. Can I reverse these grey hairs!? How to prevent these greying of hairs? Kindly help me 🙏