Under such limitations and restrictions as are prescribed by law, and in addition to jurisdiction and powers otherwise conferred, the boards of supervisors in each county may provide for the care and maintenance of the indigent sick or dependent poor of the county, and may provide medical and dental care and health services and supplies to persons in need thereof who are unable to provide the same for themselves, and for these purposes may levy the necessary taxes. Each county may, insofar as it is able to do so, provide the means to meet promptly and adequately the health needs of the indigent sick, the aged, and the poor, for the better prevention of serious illness and incapacity, to the end that such persons will not become public charges at the greater expense of those resources set aside for the public health and welfare.