A98032

Serum vitamin B12 and corresponding folate levels were analysed by Access Immunoassay Systems 33,000 and A98032, respectively (Beckman Coulter, Brea, CA, USA); LDL cholesterol was measured indirectly using the Friedewald equation; total cholesterol was measured with CHO2I: ACN 8798 and CHO2A: ACN 8433 in vitro tests; triglycerides were measured with the TRIGL: ACN 8781 in vitro test; cobas® analyser; HbA1c was measured with the A1-W3: ACN 881 in vitro test on a cobas® analyser; creatinine was measured with the CREJ2: ACN 8690 in vitro test; cobas® analyser while the estimated glomerular filtration rate (eGFR) was derived using the Modification of Diet in Renal Disease Study (MDRD) equation.
B12 deficiency was defined as B12 level < 150 pmol/L [5 , 6 (link), 35 (link), 36 (link)] whilst folate deficiency was defined as a folate level ≤ 13.4 nmol/L [37 (link)].

Serum vitamin B12 and folate were analysed by Access Immunoassay Systems 33000 and A98032, respectively (Beckman Coulter, Brea, CA, USA). Homocysteine was analysed with the ARCHITECT Homocysteine Assay 1L71 (Abbott, Wiesbaden, Germany). 25-OH-vitamin D was measured with the 25-Hydroxyvitamin D ¹²⁵I RIA Kit (68100E; DiaSorin Inc, Stillwater, MN, USA). Serum albumin and total protein were measured with the ALB2: ACN 8413 and TP2: ACN 8678 in vitro tests, respectively, on a cobas® c 701/702 analyser (Roche Diagnostics, Mannheim, Germany).
Vitamin B12 deficiency and elevated homocysteine (hyperhomocysteinaemia) were defined as <150 pmol/l [17 (link), 18 (link), 33 (link), 34 (link)] and ≥15.0 μmol/l, respectively [35 (link)]. Folate deficiency was defined as <13.5 nmol/l based on the laboratory’s chosen definition, vitamin D deficiency as <49.9 nmol/l and vitamin D insufficiency as ≥49.9 nmol/l and <74.1 nmol/l [13 (link)].