Skip to content

: Vitamin B12 24-Hour Intake Assessment

Published: August 9, 2026Updated: August 16, 2026

: This test estimates how much vitamin B12 you took in over a 24-hour period, typically from a food or supplement record rather than a blood draw.

Quick summary

[": It reflects your recent dietary B12 intake, not your body's stored vitamin B12 levels."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
81062-2
Short code
Vit B12 intake 24h Est
Synonyms
Vit B12 intake 24h Est
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Ref low
20
Ref high
400
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
estimated
CPT
82670
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

: What This Test Represents

: The result summarizes vitamin B12 consumed from foods and supplements during a single 24-hour window. It is an intake measure, meaning it is based on what you reported eating or taking, not on a chemical measurement of your blood.

: How It Differs From a Blood B12 Test

: A blood vitamin B12 test measures the amount of the vitamin circulating in your body. This 24-hour intake assessment instead describes what you consumed, so it can be normal even when body stores are low, or high without any health problem.

: Why Your Care Team May Use It

: Clinicians and dietitians use intake information to understand dietary patterns, spot possible shortfalls, and plan nutrition support. It is often combined with other information rather than used alone to diagnose a deficiency.

: How to Prepare and Report Accurately

: Keep a careful record of everything you ate and drank, including fortified foods and any vitamin supplements, with amounts and timing. Accuracy of the report strongly affects how meaningful the result is.

Reference range

Premenopausal: 20-400 pg/mL; Postmenopausal: <30 pg/mLN/A

Specimen: serum

No special preparation usually required. Stay well hydrated. Inform your healthcare provider of all medications and supplements you are taking.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

: Vitamin B12 Intake (24 h)

Frequently asked questions

: Does this test measure the vitamin B12 level in my blood?
: No. It estimates how much vitamin B12 you consumed in the last 24 hours from food and supplements, not the amount stored or circulating in your body.
: Should I change my diet based on this result alone?
: No. Discuss the result with your clinician or dietitian, who can interpret it together with your health history and any other tests.
: What if I forgot to include a supplement I take?
: Tell your care team, because missing a supplement can make your reported intake look lower than it really was, which may affect interpretation.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy