DR1IB12A
Compatible with harmonizationmoderate confidence
Dietary
Added vitamin B12 (mcg)
- Source releases
- 10
- Available cycles
- 2003-2004 · 2005-2006 · 2007-2008 · 2009-2010 · 2011-2012 · 2013-2014 · 2015-2016 · 2017-2018 · 2017-2020 · 2021-2023
- Dataset
- Dietary Interview - Individual Foods, First Day
No blocking method discontinuity is identified inside the selected cycle span, but one or more longitudinal changes require explicit harmonization conditions before pooling.
Evidence provenance: Praxis automated inference from indexed CDC/NCHS evidence
Evidence signals: source-derived · automated-difference
Relevant boundaries: 2003-2004 → 2005-2006 · 2005-2006 → 2007-2008 · 2007-2008 → 2009-2010 · 2009-2010 → 2011-2012 · 2011-2012 → 2013-2014 · 2013-2014 → 2015-2016 · 2015-2016 → 2017-2018 · 2017-2018 → 2017-2020 · 2017-2020 → 2021-2023
Praxis harmonization actions
- Verify merge grain, companion variables, and component-specific analytic guidance for the new file context.
- Review the adjacent codebooks/methods. Keep this boundary as documentation variation unless source evidence confirms a substantive method or instrument change.
- Select the weight appropriate to each cycle and subsample; when pooling cycles, construct the combined weight according to NHANES guidance rather than reusing a single-cycle weight unchanged.