# Vitamin panel: what vitamin D, B12, and folate mean

> Doctano turns the lab reports you already have into one private, source-linked health timeline, with an AI that answers from your own results.

Three nutrients, three different measurements, and a blood count that often gives the result its context.

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A vitamin panel groups three blood tests: 25-hydroxyvitamin D, vitamin B12, and folate. Each measures a different nutrient, and each is read against its own printed range. The panel is often ordered in a general health check, and it does not by itself confirm or exclude a deficiency.

Because the three tests share a page, they are easy to read as a set of similar numbers. They are not similar: one is a storage measure, and the other two are circulating vitamins with separate roles and separate units.

## What the panel measures

Vitamin D, vitamin B12, and folate are separate nutrients with separate measurements. A panel groups them because they are commonly ordered in the same health check, and because B12 and folate are often read together. The grouping belongs to the laboratory, and some reports add other vitamins, minerals, or a complete blood count.

The vitamin D line is usually 25-hydroxyvitamin D, the main circulating form and the one most reports use. Vitamin B12 is measured in serum, where it travels bound to transport proteins. Folate is usually measured in serum or plasma; a red cell folate result is a different measurement, and the report should say which one was done.

## The tests inside it

| Test | Also printed as | Unit | What it reflects |
| --- | --- | --- | --- |
| [Vitamin D (25-hydroxy)](https://doctano.com/tests/vitamin-d) | 25(OH)D, 25-OH vitamin D, calcidiol | ng/mL, nmol/L | The main circulating form of vitamin D, used as the storage measure. |
| [Vitamin B12](https://doctano.com/tests/vitamin-b12) | B12, cobalamin | pg/mL, pmol/L | The vitamin present in serum, largely bound to transport proteins. |
| [Folate](https://doctano.com/tests/folate) | Serum folate, vitamin B9 | ng/mL, nmol/L | Circulating folate, measured in serum or plasma rather than in red cells. |

A blood count is not part of the vitamin panel, but it is often ordered on the same report. The red cell lines describe the cells these nutrients support, and that context matters when the vitamin lines are read. The [complete blood count](https://doctano.com/panels/complete-blood-count) has its own page.

## Why this page does not print a range

Vitamin ranges are not interchangeable. Laboratories use different assays and different units, and a range can be stratified by age, sex, pregnancy, or the population the laboratory serves. A value copied from another report or another country is not your range.

The range printed on the report that produced your value is the one that applies. Doctano keeps that printed range with the result and does not replace it with a general range from the internet. Where a report prints a separate range for a group, read the one that matches the report's own labelling.

## What moves together

Vitamin D is a storage measure. The 25-hydroxy form reflects what is available over time rather than what was taken in that day, which is why a single result is read with the season, sun exposure, and the person's circumstances.

Vitamin B12 and folate are related but distinct. Both are involved in blood cell formation and in the processing of homocysteine, and a report may print homocysteine or methylmalonic acid beside them as functional markers. They are not the same nutrient, and one can be reduced while the other is not.

The blood count gives context. Haemoglobin, MCV, and the other red cell indices describe the cells those nutrients support, and a report that groups a vitamin panel with a blood count is giving the reader a pattern rather than a set of isolated numbers. A pattern is not a diagnosis.

## How to read the report's own grouping

- **Read the order.** Reports usually print the three vitamins, then any additional markers, then remarks. Some laboratories separate the vitamins into their own blocks.
- **Find the flags.** A flag means the laboratory compared the value with its printed range. It is not a diagnosis.
- **Check for calculated values.** Some reports add ratios or derived lines beside the measured vitamins. These are built from the measured results and are not independent measurements.
- **Check the units.** ng/mL and nmol/L are different scales, and so are pg/mL and pmol/L. Do not compare numbers across units.
- **Check the specimen.** Serum folate and red cell folate are different measurements. A result labelled RBC folate is not the serum value.
- **Check the timing.** Some laboratories ask for a morning sample, and recent intake can move a vitamin level. The report may note the collection time.
- **Read the remarks.** A note about haemolysis, a repeat, or the assay can explain a result that looks out of place.

## What a flagged result means, and what it does not

A flag means the value sits outside the range the laboratory printed. It does not confirm a deficiency, and it does not show what caused the value. Intake, absorption, sun exposure, pregnancy, age, and other conditions can all contribute, and a clinician reads the result with the person's history.

A value inside the printed range is also not proof that nothing is wrong. The range describes a reference group, not an individual. The useful question is what the value is doing over time and how it sits with the rest of the report.

## The cross-year view

Vitamin results are more useful as a series than as a single panel. Compare the same test, in the same unit, from the same laboratory where possible. If one report used a different assay or a different specimen, the two numbers are not automatically comparable, even when the units match.

Season and recent intake can move vitamin D, so the same person can differ across the year. B12 and folate can change for different reasons and at different speeds, and a blood count on the same report gives the series a second dimension.

Doctano keeps each result with its printed range and places it on the profile's timeline. Names and units are normalized across labs, so the same marker lines up across years, and every point still opens the report it came from. The trend is a prompt for a conversation, not a conclusion.

## What this page is not

This page explains the panel in general. It does not interpret your result, diagnose a deficiency, or recommend treatment. It is not medical advice. Verify the values and units against the original report, and discuss the result with a qualified professional.

## Vitamin panel questions

**What does a vitamin panel test?**

It usually groups 25-hydroxyvitamin D, vitamin B12, and folate. Some reports add other vitamins or a blood count, and the panel heading on the report shows exactly which tests were included.

**Why are vitamin D, B12, and folate tested together?**

They are often ordered in the same health check, and B12 and folate are commonly read alongside each other. Grouping them does not mean they measure the same thing, and each has its own unit, method, and printed range.

**Do I need to fast for a vitamin panel?**

Fasting is not usually required for these tests, but the laboratory's instructions decide. Some laboratories ask for a morning sample, and the report may note the collection time. Follow the instructions that came with the order.

**Can I compare vitamin results from two labs?**

Only with care. Assays and units differ, and so do the ranges. Compare the same test in the same unit, and treat the range printed on each report as the one that applies to that sample.

## Limits

**This is not a diagnosis.** A vitamin panel is read with your history, other results, and the range printed on your report. Verify the values against the original report and discuss them with a qualified professional.

## Links

- [Homepage](https://doctano.com/)
- [Lab report tracker](https://doctano.com/lab-report-tracker)
- [All panels](https://doctano.com/panels/)
- [Vitamin D](https://doctano.com/tests/vitamin-d)
- [Vitamin B12](https://doctano.com/tests/vitamin-b12)
- [Folate](https://doctano.com/tests/folate)
- [Diabetes panel](https://doctano.com/panels/diabetes-panel)
- [Cardiac risk panel](https://doctano.com/panels/cardiac-risk-panel)
- [Reference ranges](https://doctano.com/guides/reference-ranges)
- [How to read a lab report](https://doctano.com/guides/how-to-read-a-lab-report)
- [All guides](https://doctano.com/guides/)