What does this LOINC code represent?

This LOINC code identifies a lab observation, measurement, question, or clinical concept in a standardized format.

Is this enough to understand my test result?

No. The code identifies the test or observation, but the interpretation depends on the actual result, reference range, and clinical context.

LOINCActiveObservation

LOINC Code 40064-8: Calcium pre Unsp challenge [Mass/Vol]

Name: LOINC Code 40064-8: Calcium pre Unsp challenge [Mass/Vol]
Creator: HealthAssure Clinical Team
Published: 2026-05-21T08:59:27.144Z

40064-8 is a LOINC code used to identify Calcium pre Unsp challenge [Mass/Vol] in laboratory and clinical observation data. You may see this code in lab systems, lab reports, EHR exports, interoperability feeds, or other structured clinical data exchanges. LOINC codes identify tests, measurements, observations, survey items, and clinical questions in a standardized way. It is associated with the component Calcium^pre XXX challenge. It is commonly used with the system or sample type Ser/Plas.

Reviewed by HealthAssure Clinical TeamUpdated 21 May 2026

What is this code?

LOINC codes identify tests, measurements, observations, survey items, and clinical questions in a standardized way. It is associated with the component Calcium^pre XXX challenge. It is commonly used with the system or sample type Ser/Plas.

When is it used?

Used in lab systems, EHRs, and clinical data exchange.
May identify a test, observation, survey item, or clinical document request rather than a diagnosis.
Status: ACTIVE
Order vs observation: Observation

What it does not mean

The code identifies the observation or test, not the actual result.

Key facts

Calcium [Mass/volume] in Serum or Plasma --pre XXX challenge
Calcium^pre XXX challenge
Before; Ca; Cal; CHEMISTRY.CHALLENGE TESTING; Level; Mass concentration; Pl; Plasma; Plsm; Point in time; pre chal; QNT; Quan; Quant; Quantitative; Random; SerP; SerPl; SerPlas; Serum; Serum or plasma; SR

Where you may see this code

You may see this code in lab systems, lab reports, EHR exports, interoperability feeds, or other structured clinical data exchanges.

Common synonyms

Calcium pre Unsp challenge [Mass/Vol]Calcium [Mass/volume] in Serum or Plasma --pre XXX challengeCalcium pre chal SerPl-mCncCalcium^pre XXX challengeCHALCalcium before challenge, BloodMCnc

Frequently asked questions

Code details

Code40064-8

SystemLOINC

Display nameCalcium pre Unsp challenge [Mass/Vol]

DescriptionCalcium^pre XXX challenge

Short nameCalcium pre chal SerPl-mCnc

ComponentCalcium^pre XXX challenge

PropertyMCnc

TimingPt

System (specimen)Ser/Plas

ScaleQn

ClassCHAL

Example unitsmg/dL

StatusACTIVE

Order/ObservationObservation

Flags

BillableNo

Valid clinical useNo

Source

SourceLOINC

Version2.82

Releasemain

First released2.15

Last changed2.70

Consumer names

Calcium before challenge, Blood

Part names

Calcium^pre XXX challengeMCncPtSer/PlasQnMass ConcentrationPoint in time (spot)Serum or Plasma

About this content

This page is prepared by HealthAssure's clinical team using official coding standards from LOINC. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.