Vegetarians don’t necessarily have less hair, but many people who make the transition to vegetarianism or veganism experience some hair loss because of the shortage of some nutrition or other factors. Diet does play a large part in hair health, and two most common deficiencies that you might be seeing in your diet that is causing this hair loss would be Zinc and B-12.
The good news is the Zinc is naturally found in beans, nuts, milk and lots of other vegetarian-friendly foods. A B-12 deficiency tends to show up more as dandruff and less as hair loss than a Zinc deficiency. Most B-12 is found in animal products, but some fermented soy products will have it too. A multivitamin might be your best way to rule out if this hair loss is diet related. If hair loss persists even after taking multivitamins, you need to look elsewhere to pinpoint the causes of your hair loss.