The computer system and computer-implemented method of generating and providing skin care product recommendations to a subject, wherein the method comprises determining, by a computing device, a UV-B exposure of the subject; determining, by the computing device, a vitamin D intake due to the UV-B exposure; determining, by the computing device, a target vitamin D of the subject; and providing, by the computing device, a skin care product recommendation to the subject when the vitamin D intake due to the UV-B exposure is less than the vitamin D target of the subject.