I. Each insurer that issues or renews any policy of group accident or health insurance providing benefits for medical or hospital expenses, shall provide to each group, or to the portion of each group comprised of certificate holders of such insurance who are residents of this state, coverage for the provision of nonprescription enteral formulas for the treatment of impaired absorption of nutrients caused by disorders affecting the absorptive surface, functional length, or motility of the gastrointestinal tract. Such coverage shall be provided when the prescribing physician has issued a written order stating that the enteral formula is needed to sustain life, is medically necessary, and is the least restrictive and most cost effective means for meeting the needs of the patient.