VITAMIN B12 STATUS RELATES TO VITAMIN B12 INTAKE IN DANISH ELDERLY WOMEN
Bor MV 1,2, Lydeking-Olsen E 3, Møller J 4, Nexø E 1. 1Dept. Clinical Biochemistry, Aarhus University Hospital 2Dept. Clinical Biochemistry, Aalborg Hospital, 3Institute for Optimum Nutrition, Copenhagen and 4Dept. Clinical Biochemistry Skejby Hospital, Denmark
Aims: To examine the associations between vitamin B12 intake and vitamin B12 status in Danish elderly postmenopausal women.
Methods: Serum vitamin B12, vitamin B12 saturated with transcobalamin (holo-TC), TC saturation (holo-TC/total TC), methylmalonic acid (MMA) and homocysteine (HCY) were used to assess vitamin B12 status and the dietary intakes of vitamin B12 (from food and vitamin supplement) were determined in subjects (n=98, age 41-75y) by using seven-day weighed food records.
Results: The total intake of vitamin B12 ranged from 1.2 µg-23.9 µg/d. Only 4 of the 98 subjects (4 %) had intake below the Recommended Daily Allowance level of 2.4 µg. Those taking supplements (54%) had significantly higher total vitamin B12 intakes and higher vitamin B12 and TC saturation, and lower MMA and HCY concentrations than those not taking supplements. Total vitamin B12 intake correlated significantly with all vitamin B12 related parameters, whereas only serum vitamin B12 and TC saturation were significantly associated with the dietary intakes of vitamin B12. All the subjects were divided into quintiles ranked by their total vitamin B12 intake. For all the analyzed parameters the diet curves appeared to level off at approximately 6 µg/d.
Conclusion: Vitamin B12 status as judged by available laboratory tests associates with vitamin B12 intake. A daily vitamin B12 intake of 6 µg/d appears to be sufficient to correct all the vitamin B12 related parameters.