Whole blood mineral analysis – magnesium, zinc, selenium test

Magnesium is involved in hundreds of enzyme reactions and is needed, among other things, for muscles, nerves and heart rhythm. Deficiency can cause disorders of the muscles, heart and nervous system (PubMed 26404370).

Most magnesium is located in bone, muscle and cells; serum contains less than one percent of the total and is kept tightly constant by the body. A serum value can therefore be normal even though stores are depleted (PubMed 42647115). Which measurement best reflects magnesium status is, however, unresolved: serum, red blood cells, whole blood and loading tests each have their own weaknesses (PubMed 30200431). A low whole blood value is therefore an indication, not proof of deficiency.

Zinc is needed by more than 300 enzymes and is important for the immune system. A review names growth retardation, impaired immune defence and impaired cognitive function as the main consequences of deficiency. Deficiency occurs, among other things, with impaired absorption in the gut and with liver and kidney diseases (PubMed 23493534).

Skin, hair and nails can also be affected by zinc deficiency (PubMed 31144371). A single value is considered together with complaints and other findings.

Selenium is a component of selenoproteins that, among other things, have antioxidant effects and are involved in producing active thyroid hormone. Low selenium status has been associated with weaker immune function, cognitive decline and higher mortality (PubMed 22381456).

The U-shaped relationship matters: additional selenium may benefit people with low status but can harm those with adequate or high status; for example, a higher risk of type 2 diabetes is discussed (PubMed 22381456). A high value is therefore not "better".

Copper is needed, among other things, for blood formation, connective tissue and the nervous system. Copper deficiency is rare but increasingly recognised, for example after gastric bypass surgery. Typical consequences are anaemia and damage to the spinal cord and nerves (myeloneuropathy) (PubMed 31209935).

An elevated copper value is non-specific and is assessed by a doctor.

Most of the iron in the blood is in the red blood pigment (haemoglobin). The iron value in whole blood therefore depends strongly on how much haemoglobin is in the blood. It does not show iron stores: ferritin is the established marker for diagnosing iron deficiency (PubMed 25946282).

For the question of iron deficiency or anaemia, a blood count and ferritin from a doctor's practice are therefore more informative than this test.

Potassium is located mainly inside cells, sodium mainly outside. Whole blood and serum values therefore differ fundamentally for these electrolytes. Acute disorders – too high or too low potassium, sodium or calcium – are measured in serum or plasma in medicine. They can trigger heart rhythm disorders and are sometimes emergencies (PubMed 9672294, PubMed 21660912).

This test is not suitable for investigating such disorders. With palpitations, muscle weakness, signs of paralysis or confusion, the measurement belongs at a doctor's practice or emergency department.

Serum is the liquid part of the blood without blood cells; it is used for most mineral values at a doctor's practice. Whole blood, by contrast, contains blood fluid and blood cells, mainly red blood cells. For minerals located mainly inside cells, such as potassium, magnesium or zinc, whole blood therefore gives a different picture than serum.

To put it honestly: whole blood is not the same as "the body's cells". What is measured are mainly red blood cells, not muscle, nerve or organ cells. The values marked "korr." are converted by the laboratory to a standard proportion of blood cells. Whole blood analysis is not a standard method in medical guidelines; for magnesium, for example, no method is considered clearly superior (PubMed 30200431).

A mineral analysis measures the concentration of minerals and trace elements in the blood. This analysis determines eight values: the electrolytes sodium, potassium, calcium and magnesium, and the trace elements iron, copper, zinc and selenium. The laboratory measures by atomic absorption spectrometry (AAS) or, for iron, by ICP methods and compares the values with its reference ranges.

The report is a snapshot: diet, supplements, fluid balance and inflammation influence the values.

At a doctor's practice, minerals are usually determined in serum, often together with a blood count, ferritin and kidney values. That is the standard for detecting acute disorders and iron deficiency (PubMed 25946282). The whole blood mineral analysis adds a different perspective on minerals located mainly inside cells.

It does not replace a medical blood test if you have complaints.

Research associates deficiency of the measured minerals with the following complaints, with varying strength of evidence:

• Magnesium deficiency: disorders of muscles, heart and nervous system; low levels have been associated with high blood pressure, type 2 diabetes and migraine – observed in studies (PubMed 26404370).
• Zinc deficiency: growth problems, susceptibility to infection, changes in skin, hair and nails – well documented in pronounced deficiency (PubMed 23493534, PubMed 31144371).
• Selenium deficiency: weaker immune function; relevance for the thyroid – observed in studies (PubMed 22381456).
• Copper deficiency: anaemia, numbness and gait disorders due to nerve damage – well documented but rare (PubMed 31209935).
• Iron deficiency: fatigue and reduced exercise capacity due to anaemia – well documented; it is diagnosed via ferritin and a blood count (PubMed 25946282).
• Potassium disorders: heart rhythm disorders – well documented, belong at a doctor's practice (PubMed 21660912).

These are associations from studies and textbook knowledge, not causes in an individual person. A blood test cannot explain complaints and does not provide a diagnosis. Persistent complaints should first be assessed by a doctor.

With palpitations or a racing heart, pronounced muscle weakness, signs of paralysis, seizures, confusion, severe diarrhoea or vomiting over several days, the first step is a doctor's practice or emergency department, not a self-test. The same applies to numbness and unsteady gait, blood in the stool or heavy menstrual bleeding with fatigue and pallor.

With kidney diseases, after stomach or bowel surgery and with medication that affects mineral balance, such as diuretics, mineral values belong in medical care.

This page does not recommend supplements, diets or therapies. Whether a value means anything at all and which steps make sense depends on your overall situation: complaints, previous illnesses, medication and diet. More is not automatically better: with selenium, for example, additional intake can be harmful when status is already adequate (PubMed 22381456).

What makes sense for you belongs in a conversation with the ORY expert team or with your doctor or naturopath, for example from the ORY expert network. The results consultation is included in the price.

You do not need to fast. Drink 1–2 glasses of water beforehand and warm your hand. Fill in the request form and stick the barcode on the tube. Clean the side of the fingertip of your middle or ring finger with the alcohol swab, let the alcohol evaporate, prick the side of the tip and wipe away the first drop.

Fill the heparin tube up to the 400 µl mark without squeezing, close it immediately and swirl it gently 5–10 times so that the heparin mixes. Send the sample on the same day if possible, from Monday to Thursday, and do not store it in heat or sunlight.

Analysis usually takes 7–21 days from the arrival of the sample at the laboratory. As soon as your report is ready, we let you know. A results consultation with the ORY expert team is included in the price.

The whole blood mineral analysis costs €75 including VAT, shipping, return postage and results consultation.

Statutory health insurance in Germany generally does not cover whole blood mineral analyses you order yourself. With private insurance, reimbursement may be possible; how it works is described under "Reimbursement by private insurance".

The whole blood mineral analysis (€75) measures eight minerals and trace elements in whole blood. Vitamins are measured by the basic vitamin check (€98.50). The OM Vital blood test (€205) combines vitamins with blood lipids, liver and kidney values, hs-CRP and TSH. For the question of heavy metal exposure there is the heavy metal urine test (€150), for iodine the iodine test (€78).

Which scope makes sense for you can be clarified in the free initial consultation.