24-Hour Vitamin D Intake Assessment (Qualitative or Quantitative Substance Content)
This test measures how much vitamin D you consume over a 24-hour period, often checked if you have concerns about dietary vitamin D intake or vitamin D deficiency.
["This test helps determine if your vitamin D needs are being met through food alone."]
Key facts at a glance
- LOINC
- 81929-2
- Short code
- Vit D intake 24h Est
- Synonyms
- Vit D 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 Measures
This test evaluates the total vitamin D content in your recent diet. Vitamin D is primarily obtained from fortified foods, fatty fish, egg yolks, and supplements. The test may be qualitative (yes/no) or quantitative (amount consumed), depending on the lab’s method.
Why It’s Done
Your healthcare provider may order this test if you suspect low vitamin D intake, follow a restricted diet, or are evaluating vitamin D status alongside blood tests (e.g., 25-hydroxy vitamin D). It’s not a replacement for blood vitamin D levels but supports dietary assessment.
Sample Collection and Preparation
You’ll typically provide a 24-hour food log or urine sample (sometimes) to estimate vitamin D intake. Some labs may use a dietary questionnaire or food diary instead of a specimen. Follow your provider’s instructions precisely.
What to Expect Before the Test
No special preparation is usually needed, but avoid altering your usual diet for 24 hours before reporting. If using supplements, note their intake in your log.
Reference range
Premenopausal: 20-400 pg/mL; Postmenopausal: <30 pg/mLN/A
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 D Dietary Intake (24h)
Frequently asked questions
Why might my doctor ask for this test?
A low result suggests insufficient vitamin D intake, while a high result may indicate overconsumption (e.g., from fortified foods or supplements). Neither result alone diagnoses deficiency—always discuss results with your provider.
No. Blood tests (e.g., 25-hydroxy vitamin D) measure vitamin D in your body, while this test assesses intake. Both are useful—your provider may recommend both for a full picture.
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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