Meh sounds like a scam to me.
You should ensure you're healthy by getting enough vitamins, yes, but "hair vitamins" etc are just scams. Multivitamins are cheaper and cover more bases, and vitamins do very little for MBP. They'd only grow hair if you were extremely defficient in something.
I'd say get enough vitamins through your diet and a multivitamin, antioxidants are also very important, however controlling blood sugar would probably be the best thing you could do diet-wise against male pattern baldness. Insulin resistance is known to affect hair loss, acne, and other androgen related problems.