Since there is ZERO evidence that fluoride acts systemically to reduce tooth decay and since fluoride vitamins and supplements are NOT FDA approved this recommendation seems far afield from standard medical practices.
It is malpractice for an doctor licensed to practice in the US to prescribe unapproved drugs that can and do have an adverse systemic effect (dental fluorosis among others).
Published in the Federal register the FDA rejected one New Drug Applications (NDA) for systemic fluoride vitamins in 1975 and allowed 35 others to be "voluntarily" withdrawn.
NDA withdrawn for fluoride and vitamin combinations
Drug Therapy June 1975
"The FDA has addressed a ”regulatory letter” to approximately 35 companies marketing combination drugs consisting of fluoride and vitamins. The letter states that these drugs are related to a product (Ernziflur lozenges) for which FDA has withdrawn approval of a new drug application. The NDA for Enziflur was withdrawn because there is no substantial evidence of drug effectiveness as prescribed, recommended, or suggested in its labeling.
The FDA has therefore advised manufacturers of combination fluoride and vitamin preparations that their continued marketing is in violation of the new drug provisions of the Federal Food, Drug, and Cosmetic Act; they have, therefore, requested that marketing of these products be discontinued."