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All biomarkers
Nutritional

Vitamin B12 (cobalamin)

Measured in pg/mL · LOINC 2132-9

Reference ranges

Optimal
5001500 pg/mL
functional-medicine target
Standard
200900 pg/mL
lab reference range

Optimal ranges are tighter than standard lab ranges and reflect functional-medicine targets, not the populations they were derived from. Reference bands depend on sex, age, and circumstance — Juno's lab analysis layers your profile context onto the printed range when you paste a value.

Peptide relevance

Critical for methylation, red blood cell formation, neurological function, and energy metabolism. Standard reference range floor (200 pg/mL) is too low — clinical symptoms often present at 200-400 pg/mL despite 'normal' lab reading; functional medicine targets >500 pg/mL with methylmalonic acid (MMA) as the functional confirmation marker. Vegetarians and vegans, users on metformin, users with H. pylori or post-bariatric anatomy, and older adults run higher deficiency rates. No direct peptide effects in common stacks. Cyanocobalamin oral supplementation is unreliable for some users; methylcobalamin or hydroxocobalamin (injectable or sublingual) are better absorbed if MMA is elevated. Methylcobalamin is also one of Juno's library entries — Tier 3 standalone.

Have a recent Vitamin B12 (cobalamin) value?

Paste it on the lab analysis page. Juno reads your active stack + (if shared) your medications and conditions, and surfaces plausible contributors with citations. Doesn't diagnose.

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