A key aspect of hair loss with age is the aging of the hair follicle.  Ordinarily, hair follicle renewal is maintained by the stem cells associated with each follicle. Aging of the hair follicle appears to be primed by a sustained cellular response to the DNA damage that accumulates in renewing stem cells during aging.  This damage response involves the proteolysis of type XVII collagen by neutrophil elastase in response to the DNA damage in the hair follicle stem cells. Proteolysis of collagen leads to elimination of the damaged cells and then to terminal hair follicle miniaturization.
Multiple vitamins, including biotin, have been promoted for hair growth, but solid scientific studies for many of these claims are lacking. While taking biotin and other supplements marketed for hair, skin, and nails probably won't worsen anything, it may also not necessarily help the situation. Therefore, advertised hair-regrowth supplements should be approached with mild caution. There is only anecdotal evidence that oral or topical application garlic , onion juice, saw palmetto, coconut oil, evening primrose oil , apple cider vinegar, creatine, and pumpkin seed oil are of benefit for hair loss.