U.S. Code of Federal Regulations
Regulations most recently checked for updates: Aug 27, 2025
(a) Identification. A vitamin D test system is a device intended for use in clinical laboratories for the quantitative determination of 25-hydroxyvitamin D (25-OH-D) and other hydroxylated metabolites of vitamin D in serum or plasma to be used in the assessment of vitamin D sufficiency.
(b) Classification. Class II (special controls). Vitamin D test systems must comply with the following special controls:
(1) Labeling in conformance with 21 CFR 809.10 and
(2) Compliance with existing standards of the National Committee on Clinical Laboratory Standards.