EFFECT OF STORAGE ON SERUM VITAMIN-B-12 AND FOLATE STABILITY

To facilitate transport from remote locations, the stability of vitami n B-12 and folate was investigated in serum specimens, Serum vitamin B -12 proved to be highly unstable, emphasizing that specimens should be frozen if not analyzed immediately. Light protection is necessary if the sample cannot be analyzed within 4 hours. In contrast, folate is a more robust analyte. In refrigerated serum specimens, folate was stab le up to 7 days of storage. In situations where specimen stability is important, vitamin B-12 status is better assessed with serum or urine methylmalonic acid measurements. Although folate status can be assesse d in a similar fashion with homocysteine, specimen stability indicates that direct measurement of folate is a better strategy.