Table 2.
Serum vitamin B-12 | Serum MMA | |||||||
---|---|---|---|---|---|---|---|---|
Variable categories | 2011–2012 | 2013–20142 | 2011–2012 | 2013–20142 | ||||
n | % | n | % | n | % | n | % | |
All | 4,804 | - | 5,216 | - | 4,807 | - | 5,213 | - |
Age, y | ||||||||
20–39 | 1,670 | 35.2 | 1,705 | 35.2 | 1,670 | 35.1 | 1,703 | 35.2 |
40–59 | 1,608 | 38.8 | 1,823 | 37.4 | 1,608 | 38.8 | 1,821 | 37.4 |
60–69 | 800 | 14.0 | 866 | 14.8 | 800 | 14.0 | 867 | 14.8 |
≥70 | 726 | 12.0 | 822 | 12.6 | 729 | 12.1 | 822 | 12.6 |
Sex | ||||||||
Male | 2,424 | 49.1 | 2,535 | 49.3 | 2,424 | 49.1 | 2,534 | 49.3 |
Female | 2,380 | 50.9 | 2,681 | 50.7 | 2,383 | 50.9 | 2,679 | 50.7 |
Race-ethnicity | ||||||||
Hispanic | 974 | 14.3 | 1,172 | 14.7 | 974 | 14.3 | 1,174 | 14.8 |
Mexican American | 481 | 7.8 | 709 | 9.2 | 481 | 7.8 | 711 | 9.2 |
Non-Hispanic Black | 1,220 | 10.8 | 1,026 | 10.8 | 1,220 | 10.8 | 1,024 | 10.8 |
Non-Hispanic White | 1,805 | 67.4 | 2,279 | 66.6 | 1,807 | 67.4 | 2,275 | 66.6 |
Non-Hispanic Asian | 670 | 5.0 | 588 | 5.2 | 671 | 5.0 | 589 | 5.3 |
B-12 supplement use | ||||||||
No | 3,303 | 66.1 | 3,514 | 64.1 | 3,304 | 66.0 | 3,515 | 64.1 |
Yes | 1,467 | 33.9 | 1,672 | 35.9 | 1,469 | 34.0 | 1,668 | 35.9 |
Fasting | ||||||||
<3 h | 1,347 | 29.4 | 1,689 | 35.5 | 1,347 | 29.4 | 1,688 | 35.5 |
3–<8 h | 982 | 18.7 | 983 | 16.8 | 983 | 18.7 | 980 | 16.8 |
≥8 h | 2,475 | 51.9 | 2,544 | 47.7 | 2,477 | 51.9 | 2,545 | 47.7 |
Renal function | ||||||||
Normal | 3,730 | 82.2 | 3,989 | 80.1 | 3,731 | 82.2 | 3,987 | 80.1 |
CKD stage 1–2 | 613 | 10.6 | 693 | 11.8 | 614 | 10.6 | 693 | 11.8 |
CKD stage 3–5 | 424 | 7.3 | 482 | 8.1 | 425 | 7.3 | 481 | 8.1 |
Values are weighted percentages. Pregnant and lactating women were excluded; available-case analysis was used to handle missing or incomplete data (e.g., B-12 supplement use, renal function). CKD, chronic kidney disease; MMA, methylmalonic acid.
While NHANES 2013–2014 collected samples from participants ≥19 y of age, we only included data for participants ≥20 y of age.