Table 4.
Serum vitamin B-12 and methylmalonic acid concentrations by Dietary Reference Intake age groups in US persons ≥19 y of age, NHANES 2011–20141
| Percentiles | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Analyte Age group | n2 | Geometric mean (95% CI) | 2.5 | 5 | 10 | 25 | 50 | 75 | 90 | 95 | 97.5 |
| B-12, pmol/L | |||||||||||
| 19–50 y | 5,457 | 374 (369, 380) | 163 | 190 | 219 | 281 | 369 | 489 | 633 | 752 | 885 |
| ≥51 y | 4,694 | 408 (399, 418) | 153 | 176 | 213 | 282 | 392 | 561 | 791 | 1040 | 1440 |
| P value | 0.0064 | ||||||||||
| MMA, nmol/L | |||||||||||
| 19–50 y | 5,455 | 133 (131, 136) | 67.5 | 74.4 | 83.0 | 103 | 129 | 165 | 214 | 263 | 338 |
| ≥51 y | 4,696 | 175 (171, 179) | 79.8 | 90.3 | 103 | 127 | 164 | 220 | 317 | 420 | 558 |
| P value | <0.0001 | ||||||||||
1
NHANES 2011–2012 collected samples from participants ≥20 y of age, while NHANES 2013–2014 collected samples from participants ≥19 y of age. Serum vitamin B-12 was measured by Roche E-170 immunoassay and serum MMA by HPLC-MS/MS. Pregnant and lactating women were excluded. P values are based on Wald F test. B-12, vitamin B-12; MMA, methylmalonic acid.
2
Sample size