Vitamin A deficiency has been a trigger of impotence in some males. Vitamin A! "Vitamin A deficiency has been the trigger of impotence in some men," states Elson Haas, M.D., Director of the Preventive Healthcare Center. Much more often than not Erectile Dysfunction is short-term. Muira Puama for instance assists a man have tougher erections and elevated libido simply because it is considered a nerve stimulant.