Biomarkers · Vitamins & Endocrine

Vitamin B12 (Cobalamin)

Both low and high values go with higher risk of death. Not measured in our NHANES panel. The curve is drawn from the published study (source below).

Cobalamin and risk of death

Published curve higher than the NHANES fitNHANES fit higher

Risk of death relative to the curve's reference value, drawn from the published study (source below).

Published risk of death1.30×high (>90th percentile) vs middle (10th-90th percentile) serum vitamin B12 (95% CI 1.03–1.64) · Chinese Longitudinal Healthy Longevity Survey, participants aged >65 (mean 87.74 y), 2011-2014 waves

Cobalamin by age and sex

Each bar runs from the 5th to the 95th percentile, the darker part from the 25th to the 75th, and the tick is the median. Not a reference range or a target.

The percentiles as a table

Each row is one sex and age band: the values below which 5%, 25%, 50%, 75% and 95% of people fall (pg/mL), from the survey named in the row. Not a reference range or a target.
Sex	Age	5th	25th	Median	75th	95th	n	Cycle / source
All	20-39	263	381	496	656	974	1,739	NHANES 2013-2014
All	40-59	248	381	498	680	1,240	1,828	NHANES 2013-2014
All	60+	229	380	545	762	1,501	1,688	NHANES 2013-2014
All	all	250	381	509	694	1,204	5,255	NHANES 2013-2014
Men	20-39	283	399	505	665	954	872	NHANES 2013-2014
Men	40-59	255	378	485	618	1,078	859	NHANES 2013-2014
Men	60+	207	360	502	692	1,100	804	NHANES 2013-2014
Men	all	261	382	496	657	1,029	2,535	NHANES 2013-2014
Women	20-39	242	362	485	647	997	867	NHANES 2013-2014
Women	40-59	237	384	516	730	1,407	969	NHANES 2013-2014
Women	60+	244	402	587	870	1,763	884	NHANES 2013-2014
Women	all	240	380	521	734	1,381	2,720	NHANES 2013-2014

What studies found when this marker was changed

They describe what happened in those study groups, not a recommendation. See all catalogued interventions.

Measured changes in Cobalamin, study by study

2 effects with a numeric size, each from one study arm: the dot is the reported change, the line its 95% interval where one was given. Study results in the groups studied, not predictions for a person.

Each row is one study: what was changed, the effect it reported on this marker, and the source.
Type	Intervention	Reported effect	Evidence	Source
supplement	Oral methylcobalamin 1 mg daily for one year in metformin-treated type 2 diabetes patients with diabetic neuropathy and B12 <400 pmol/L	Plasma B12 rose from 232.0 to 776.7 pmol/L over one year (p < 0.0001) with no change on placebo; nerve conduction, vibration threshold and pain improved	RCT	Didangelos T, Karlafti E, Kotzakioulafi E, et al. Vitamin B12 Supplementation…
supplement	Two tablets daily (each PEA 300 mg, SOD 70 IU, alpha-lipoic acid 300 mg, B6 1.5 mg, B1 1.1 mg, B12 2.5 ug, vitamin E 7.5 mg, nicotinamide 9 mg, Mg 30 mg, Zn 2.5 mg) for 6 months in type 2 diabetes with neuropathy	Serum B12 rose from 222.1 to 576.3 pg/mL over 6 months in the active group (p < 0.001), change differing from placebo (p = 0.025); pain score 20.9 -> 13.9	RCT	Didangelos T, Karlafti E, Kotzakioulafi E, et al. Efficacy and Safety of the…

Sources

Risk curve: Xu K 2021 (PMID 34530742): all-cause HR 1.3 (1.03-1.64) high (>90th percentile) vs middle (10th-90th percentile) serum vitamin B12. Scaled to US values (NHANES).
Xu K, Liu X, Liu J, Zhang Y, Ding X, Li L, Sun J. Association between serum vitamin B12 and risk of all-cause mortality in elderly adults: a prospective cohort study. BMC Geriatrics. 2021.

Map Vitamin B12 (Cobalamin) against another biomarker.

Map Cobalamin against another marker