Table 1.

Selected published reference intervals for serum or plasma methylmalonic acid

Author (year) [Reference]	Population	Central 0.95 reference interval, nmol/L	Additional information
Allen 1990 [10]	Healthy U.S. middle-aged adults	73–271	Men and women, n=50; 18–65 y
Rasmussen 1990 [11]	Healthy Danish middle-aged adults	50–370	Men and women, n=58; 40–68 y (median: 53 y)
Rasmussen 1996 [4]	Healthy Danish middle-aged adults before and after vitamin B-12 supplementation for 1 wk (in a few cases for 2 wk)	80–280	Men (n=109) and women (n=126); 20–84 y (men; median: 50 y) and 20–85 y (women; median: 49 y); all but 1 subject had plasma creatinine concentrations within the reference interval for healthy subjects
Joosten 1996 [5]	Healthy Belgian, Dutch, and German middle-aged adults Healthy Dutch elderly living at home Healthy German elderly after B-vitamin supplementation for 3 wk	62–247 72–476 55–278	Men and women, n=99; 19–55 y (mean: 30 y) Men and women, n=64; 65–88 y (mean: 76 y); no participant had creatinine clearance <30 mL/min Men and women, n=143; 65–96 y (mean: 75 y); no participant had creatinine clearance <30 mL/min
Lewerin 2003 [12]	Swedish elderly with and without B-vitamin supplementation  Total study group at baseline  Healthy elderly at baseline  Healthy elderly after B-vitamin supplementation for 4 mo	110–480 120–380 20–340	Men and women, n=209; 70–88 y (women) and 70–93 y (men) (overall median: 76 y)  n=208  n=123  n=78 (vitamin B-12 replete)
Milman 2007 [13]	Healthy Danish pregnant women  18 wk gestation  32 wk gestation  39 wk gestation  8 wk post-partum	40–290 50–340 60–360 80–350	Women (n=434) with a normal pregnancy ≥37 wk  n=413  n=390  n=250  n=160
Vogiatzoglou 2009 [14]	Norwegian middle-aged adults:  Unselected  Vitamin B-12 ≥200 pmol/L  Vitamin B-12 ≥400 pmol/L Norwegian elderly:  Unselected  Vitamin B-12 ≥200 pmol/L  Vitamin B-12 ≥400 pmol/L	100–320 100–300 100–280 110–490 110–410 100–360	Men and women, n=3,684; 47–49 y  n=3,684  n=3,568  n=1,306 (vitamin B-12 replete) Men and women, n=3,262; 71–74 y  n=3,262  n=3,043  n=1,058 (vitamin B-12 replete)
Erdogan 2010 [6]	Healthy US adults US persons tested for MMA (unknown clinical history)  0–10 y  11–20 y  21–30 y  31–40 y  41–50 y  51–60 y  61–70 y  ≥71 y	60–360 0–510 30–260 50–330 50–400 50–400 50–420 50–440 50–480	Men (n=16) and women (n=24) Males and females (n=4,944); highest 10% of results disregarded (potentially unhealthy persons)  n=28  n=39  n=165  n=287  n=545  n=813  n=918  n=2149