HIGH PREVALENCE OF ELEVATED VITAMIN B12 LEVELS AT A TEACHING HOSPITAL

Abstract

<h3>Introduction</h3> Measurement of serum vitamin B12 and folate levels is an integral part of the laboratory evaluation at our geriatric psychiatry clinic. While B12 testing is typically done to detect abnormally low B12 levels, in our clinic and elsewhere the tests often detect vitamin B12 abnormalities consisting of high rather than low levels of B12. The apparent high frequency of excessively high levels of vitamin B12 at our clinic led us to explore this issue in a more systematic manner. <h3>Methods</h3> This presentation examined all the B12 results completed at Hackensack Meridian Health- Jersey Shore University Medical Center [JSUMC] in 2018 and 2019. The initial query elicited 15833 test results. All cases whose folate was low (n=58) or unavailable (n=3987) were excluded from further analysis resulting in a sample of 11787 tests. Furthermore, duplicate tests for the same individual were excluded, holding on to the earliest performed test, resulting in a sample of 8901 B12 tests across all ages. This presentation examines the interplay between three variables: Vitamin B12 level, Age, and MCV. All three parameters were examined as continuous as well as categorical variables. The three variables were converted from continuous to categorical variables as follows: B12 level (low 0-179 Pg/Ml = 132 pmol/L; normal 180-914 Pg/Ml (that is 133-677 pmol/l); high 915 Pg/Ml (677 pmo/l) and up), Age (young 0– 17 yrs; adult 18-64; senior 65 and up), MCV (low 0-79.9; normal 80-100; high 100.1 and up). The conversion ratio for vitamin B12 is is 1.35 pg/ml = 1 pmol/l. <h3>Results</h3> 1. 22% of the whole sample had above normal Vitamin B12 levels 2. 27% of Seniors (65 and older) had above normal Vitamin B12 levels 3. B12 levels correlated positively with age; Seniors (65 and older) had significantly higher (by about 20%) B12 levels compared to adults (18-64 of age) 4. 8% of Seniors had high MCV despite normal or above normal plasma B12, suggesting possible functional B12 deficiency 5. 3.3% of Seniors had normal MCV despite B12 deficiency. <h3>Discussion</h3> During a two year period over a quarter of all vitamin B12 tested patients at JSUMC in general, and seniors in particular had above normal B12 levels. Oral B12 supplements may contribute to above normal B12 plasma levels, but the literature is equivocal on this issue. Unfortunately because in this sample specific clinical data was not available regarding the B12 intake in this population, the nature of the relation between oral intake of vitamin B12 supplements and abnormal high plasma B12 levels could not be explored. Several studies have reported on the prevalence of abnormal high vitamin B12 levels: Jammal et al., 2013 found it in 12% of cases, Carmel et al.,2001 in 14% and Chiche et al., 2013 in 18% of patients. Using 914 Pg/Ml as a cutoff point resulted in 27.5 % of JSUMC seniors falling in the above normal range category well above the published results. Above normal vitamin b12 levels are known to be associated with a long list of serious conditions including: 1. Hematological malignancies / blood dyscrasias, 2. Liver diseases, 3. solid organ tumors, 4. Autoimmune disorders 5. Renal disease / kidney failure, 6. Infectious diseases 7. Possibly with excessive b12 supplements intake. 8. Increased all-cause mortality Two recent studies have reported on the relationship between serum B12 concentrations. Wolffenbuttel et al., 2020 found, that there was a small but significant increase in cardiovascular mortality in the groups with low or high serum B12. The 2020 Flores-Guerrero et al., study found "that higher levels of plasma concentrations of vitamin B12 were associated with increased risk of all-cause mortality...". <h3>Conclusions</h3> 1. Over a quarter of the seniors tested at JSUMC had abnormally high vitamin B12 levels. The reason for this higher than expected prevalence requires further exploration. 2. In addition, since elevated B12 levels are known to be associated with a long list of serious medical conditions and a higher mortality rate, this project emphasizes the importance of conducting a careful clinical review for possible serious hidden causes for such findings. 3. High vitamin B12 may be the result of oral intake of large amounts of vitamin B12 supplements, but this information is typically not systematically collected. This project also highlights the importance of collecting accurate quantitative information regarding vitamin supplement intake when completing the medication reconciliation process in routine clinical practice. 1. Andrès E, et al., 2013 PMID: 23447660. 2. Arendt JF, et al., 2013 PMID: 23241600. 3. Carmel R, et al., 2001 PMID: 11843883. 4. Jammal M, et al 2013 PMID: 2314212. 5. Chiche L, et al., 2013 PMID: 23708236. 6. Wolffenbuttel BHR, 2020 PMID: 33032595. 7. Flores-Guerrero JL, 2019 PMID: 31940038.