Bloodworks
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Electrolytes

A focused blood test of the four key electrolytes: sodium, potassium, calcium and magnesium, for insight into your fluid, nerve and muscle balance in one blood draw.

4 biomarkersReport within a few working days800+ collection points
View all 4 biomarkers
4biomarkers measured
Sodium

Electrolyte; regulates fluid balance and blood pressure.

Potassium

Electrolyte; important for heart conduction and muscle function.

Calcium

Mineral for bone, muscle and nerve function.

Magnesium

Mineral involved in muscle and nerve function and energy production.

  • 4 biomarkers measured
  • Doctor-reviewed report
  • Results within a few working days
How it works?

How Bloodworks works

  1. Order online

    Choose your package and preferred location

  2. Receive your lab form

    Within 24 hours by email, with appointment planner

  3. Schedule your blood draw

    Or choose a walk-in location

  4. Blood draw

    Takes just a few minutes

  5. Receive your report

    Securely, within a few working days from our physicians

Included

Your personal health dashboard

Sample view · fictitious data.

Within range

29/30

of the biomarkers within the lab reference

Latest measurement: 1 Jul 2026

Needs attention

Ferritine

Your development

Vitamine D3

Value (nmol/L)142.481.520.615 Jul10 Nov5 Mar961 JulDate of measurement
  • All your results in one secure place
  • See your development with every new measurement
  • Compare against your own earlier values

Included

Your laboratory report

Every abnormality is given context and advice by a doctor. Reference values always come from the laboratory.

Bloodworks
Laboratory report

Client

Reference

Collection date

06-05-2025

Report date

08-05-2025

2 abnormalities found

Magnesium & vitamin D too low, see explanation

Vitamins & Minerals

Total cholesterol4.8<5.0OK
HDL cholesterol1.4>1.2OK
LDL cholesterol2.9<3.0OK
Magnesium0.52>0.7LOW
Vitamin D18>50LOW

Doctor comment

Your magnesium and vitamin D are markedly reduced. This can contribute to fatigue, muscle cramps and lower immunity. Supplements are generally available over the counter in the Netherlands. At your levels, however, we advise read more ›

Authorised by a doctor · BIG-registeredDr. [name confidential]

Experiences

What customers say

★★★★★5,08 verified reviews
Vanuit de sportschool geattendeerd op Bloodworks en heel tevreden. Bloedonderzoek online besteld en kon direct terecht bij een lab in de buurt. Kreeg het labformulier per e-mail en na het prikken de resultaten met uitleg ontvangen. Kom hier zeker vaker terug!
SZSebas van Zeggeren6 maanden geleden
Ik heb eerder onderzoeken laten uitvoeren door andere organisaties, maar Bloodworks steekt daar met afstand bovenuit. De snelle service, het persoonlijke contact en de transparantie hebben ervoor gezorgd dat ik al mijn vervolgonderzoeken hier laat uitvoeren.
SFSam Feenstra4 maanden geleden
Na geregeld duizelig te voelen ben ik langs geweest bij Bloodworks voor een bloedtest, snelle service en super snel uitslag gekregen! Advies gekregen van de specialisten om een aantal waardes aan te vullen, en daadwerkelijk geen last meer van mijn klachten. Super dankbaar, vakkundig en bekwaam.
RDR. Du5 maanden geleden
Read all reviews

FAQ

Frequently asked questions

Do I need to fast?

Fasting is not strictly required for electrolytes, but we recommend fasting (8 hours) for a reliable picture, especially for magnesium.

What exactly are electrolytes?

Electrolytes are minerals with an electrical charge (sodium, potassium, calcium, magnesium) that are essential for fluid balance, nerve signalling, muscle function and heart rhythm.

When is an electrolyte test useful?

With complaints such as muscle cramps, palpitations, fatigue or tingling, or when using diuretics, antacids or during intensive sport.

How is this different from Vitamins, minerals and electrolytes?

This package focuses specifically on the four electrolytes. If you want a broader picture with vitamins and iron included, choose Vitamins, minerals and electrolytes.

How quickly do I get my results?

Typically within a few working days of the blood draw, including interpretation by our doctor.

89,-

All-in, blood draw included

Customer service

Questions? We are happy to help!

Available on weekdays from 9:00 – 17:00