Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Keeping Up With Folic Acid Fortification

NIST SRM 3949 Folate Vitamers in Frozen Human Serum


SRM 3949

What:  SRM 3949 is a new material with several improvements compared to the original SRM 1955. It is comprised of three levels of folates in human serum.

Why:  This SRM provides quality assurance and control for the measurement of folates in human serum.

Who:  SRM 3949 is intended for clinical laboratories, research laboratories, and in vitro diagnostics manufacturers who are performing method development and measurement of folates in human serum.

How: This SRM possesses three levels of folate in frozen serum that better reflect levels observed in the present-day population undergoing folic acid fortification. This new material also contains ascorbic acid to better stabilize the folates and is value assigned for minor folates, which are improvements over the original SRM 1955. This SRM is intended to validate methods and can also be used for qualifying in-house control materials.

Released February 19, 2019, Updated January 9, 2020