Iron deficiency
Iron deficiency starts at a ferritin below 30 µg/L, often before haemoglobin falls. We measure ferritin, saturation and the blood count. See your values.
Complaints & symptoms
Blood values for complaints and deficiencies.
Iron deficiency, anaemia, a vitamin B12 shortfall, an underactive thyroid or insulin resistance: each leaves its own pattern in your blood.
Per topic you’ll read which blood values belong to it, which reference ranges Dutch labs use, and what it is often confused with.
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10 conditions
Iron & blood count
Shortfalls that reach your oxygen transport, from the store to the red cell itself.
Vitamins & minerals
What you get from food or sunlight, and where it falls short.
Vitamin B12 deficiency
The lower limit at which a lab calls B12 too low ranges from 133 to 175 pmol/L. We measure B12 and can include MMA for extra context.
Vitamin D deficiency
A vitamin D deficiency starts below 30 nmol/L; from age seventy, below 50 already counts as a deficiency. We measure 25-OH vitamin D.
Thyroid & hormones
The thermostat of your metabolism, running fast or slow.
Underactive thyroid
An underactive thyroid shows first in TSH: above 4.2 to 5.33 mIU/L depending on the lab, above 10 almost certainly. We measure TSH and free T4.
Low testosterone
A testosterone deficiency is an average below 11 nmol/L, measured twice before ten in the morning, with complaints. We measure testosterone, SHBG and LH.
PCOS
PCOS affects about 6% of women: the ovaries make too many androgens and insulin plays a leading role. We measure LH, testosterone, SHBG and the sugar values.
Sugar & metabolism
How your body handles sugar, years before a diagnosis is made.
Liver & uric acid
Two metabolic pictures your blood gives away before your body does.
Fatty liver
Fatty liver causes no complaints and shows as a slightly raised ALT; losing 5 to 10% of your weight takes the fat out again. We measure ALT, AST and gamma-GT.
Gout
Gout arises when uric acid settles as crystals in a joint; below 0.35 mmol/L attacks stay away. We measure uric acid, kidney function and the fats.
Also without complaints. A quiet course is just as real: underactive thyroid, vitamin D deficiency, insulin resistance and fatty liver often cause nothing you would notice for a long time. That too is a finding: how you feel says little about where your values stand.
Can a blood test explain my complaint?
Not on its own. A blood test shows where your values stand; it does not say which complaint they cause. Fatigue is described at five of the ten conditions here, and each of those four is measured with different values. What a test does give you is the direction: which values are outside the range four Dutch laboratories publish, how far outside, and which of the conditions on this page that fits. The reading, and the diagnosis, belong with your GP.
Frequently asked questions
Can I have a deficiency without noticing anything?
Yes. An underactive thyroid, a vitamin D shortfall and insulin resistance often cause nothing you would notice for a long time, because the body compensates until it cannot. That is why a value can already be outside the range while you feel fine, and why how you feel says little about where your values stand.
Which values are measured for fatigue?
Fatigue is described at five of the ten conditions here, and they do not share one value. Iron deficiency shows in ferritin first, anaemia in haemoglobin, an underactive thyroid in TSH and free T4, a B12 shortfall in B12 with methylmalonic acid beside it. That is why a single value rarely settles the question and a broad measurement is the usual starting point.
What does it mean if a value is outside the reference range?
Not automatically that something is wrong. A reference range covers the middle 95 percent of a healthy group, so one in twenty healthy people falls outside it. The direction, how far outside, your other values and how they move over time say more than one marking on its own.
Do I need a referral to have this measured?
No. You can schedule a blood test yourself, without going through your GP first. You choose a priklocatie, the bloedafname takes a few minutes, and the results are in the app within 24 hours with an explanation per value.
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