You’ve tried the serums, the oils, the expensive shampoos. Your hair is still falling out. Here‘s what the ads won’t tell you: most hair loss isn‘t about what you put on your scalp. It’s about what’s missing inside your body. And the real culprit might be as simple as a B vitamin you’re not getting enough of. No expensive treatments. Here’s exactly what to do—and why it works when the shampoos don‘t.