Full nutrition blood test

Full vitamin and mineral blood test with vitamin D, vitamin B12, folic acid, iron studies, magnesium, zinc, selenium, homocysteine, proteins, general biochemistry, TSH and urine. It is designed to extend a basic nutritional assessment when there is a restrictive diet, suspected malabsorption or persistent symptoms that call for more context.

No prescription or appointment needed

Results in 3-5 working days

Blood and urine sample. Includes: Full blood count · Glucose · Urea, creatinine and eGFR · Uric acid · Sodium and potassium · Lipid profile and ratios. 19 in total. See what each one measures

What it is for

It assesses nutritional status from several angles in a single sample. It extends ferritin with full iron studies, adds trace minerals and uses homocysteine as support for interpreting B12 and folate.

It can be useful when a basic blood test does not explain the symptoms, when there is a long-standing restrictive diet or when absorption problems are suspected. Not every out-of-range result represents a clinically relevant deficiency, and serum minerals have limitations that must be taken into account.

When it is recommended

Persistent symptoms after an inconclusive basic nutrition blood test
Vegan, vegetarian or very restrictive diets kept up over time
Suspected malabsorption or a history of digestive disease
A heavy training load together with insufficient intake or compatible symptoms
Before starting broad supplementation without a specific indication

Clinical comment

Full iron studies help interpret a ferritin result that does not fit the full blood count or the symptoms. Low ferritin supports iron deficiency, but ferritin can be normal or high when there is inflammation. Transferrin saturation adds a different view of the iron that is available.

Homocysteine is included as a functional marker related to B12 and folate. It is not specific: it also rises with kidney disease, age, smoking and other factors, and lowering it does not in itself mean lowering cardiovascular risk.

We have left out vitamins A and E, copper and ionised calcium because measuring them routinely rarely changes a decision in someone without malabsorption, bariatric surgery or another specific risk factor. For those situations there is an advanced profile, marked as secondary relevance, and a dedicated post-bariatric check.

Dr. Antonio Mas

What is tested

Full blood count: Looks for anaemia and other changes in the blood cells.
Glucose: Measures fasting blood sugar.
Urea, creatinine and eGFR: Assess kidney function and add context about hydration and protein metabolism.
Uric acid: Completes the metabolic and kidney assessment.
Sodium and potassium: Measure the main electrolytes in the blood.
Lipid profile (total cholesterol, HDL, LDL, triglycerides) and ratios
AST, ALT, GGT and total bilirubin: Give information about the liver.
Ferritin: Estimates iron stores, although it can also rise with inflammation.
Iron studies (iron, transferrin, saturation and total iron-binding capacity)
Vitamin D (25-OH): Assesses vitamin D stores.
Vitamin B12: Measures the circulating level of cobalamin.
Folic acid (folate): Assesses folate, which is involved in making blood cells.
Magnesium: Measures serum magnesium, which represents only a small part of the body's stores.
Zinc: Assesses the circulating level of a mineral involved in many metabolic functions.
Selenium: Measures a trace element involved in antioxidant and thyroid enzymes.
Homocysteine: Can rise with B12 or folate deficiency, although it also changes with kidney function and other causes.
Total protein and albumin: Give information about liver synthesis, losses and protein status, but do not on their own diagnose malnutrition.
Urinalysis and sediment: Looks for protein, blood, glucose, white blood cells and other urinary abnormalities.
TSH: The first test for assessing thyroid function.

How to prepare

Fast for 8 to 12 hours. You can drink water. Bring a sample of your first urine of the morning or collect it at the partner centre. If you take biotin supplements, stop them 48 hours before, because they can interfere with several tests.

Oral iron can temporarily raise serum iron. Check whether you should have the sample taken before your dose or adjust when you take it according to the laboratory's instructions. Do not stop a prescribed treatment for a week on your own.

You can add

Without another needle. It is offered when you order, so you do not have to decide now.

Sugar, insulin and inflammationAssesses insulin resistance through fasting insulin and the HOMA-IR index, plus average blood sugar over the last three months and low-grade inflammation.+€59.00
Coeliac disease antibodiesMeasures the antibodies used to investigate coeliac disease; for a reliable result, it must be done while you are still eating gluten.+€39.00

Related blood tests

We have other profiles in Nutrition with more or fewer tests:

The most comprehensive is not always the most useful. If you are not sure, the one we recommend to start with is Basic nutrition blood test.

What it is based on

Organización Mundial de la Salud
WHO guideline on use of ferritin concentrations to assess iron status in individuals and populations
This is what supports including full iron studies and not just ferritin. The WHO warns that ferritin is an acute-phase reactant that rises with inflammation, which is why it asks for it to be measured together with CRP and for the threshold to be raised to 70 µg/L when there is inflammation. This profile does not include CRP and addresses the same issue from the other side, with iron, transferrin and transferrin saturation, which is what is done in usual clinical practice.
National Institute for Health and Care Excellence
Vitamin B12 deficiency in over 16s: diagnosis and management (NG239)
This is the B12 guideline, and the one that sets the order of tests: total B12 or active B12 as the first test and, if the result is indeterminate, methylmalonic acid. Homocysteine, which is the one this profile includes, remains an alternative with a caveat: it also rises with folic acid deficiency, so it is not read on its own. Methylmalonic acid is not currently in this catalogue.

Protocol designed by Dr. Antonio Mas, specialist in Endocrinology and Nutrition, Spanish medical licence no. 080846289, and reviewed in September 2026.

This blood test is a standardised protocol and does not replace a medical consultation. If you have symptoms, a known condition or a complex clinical situation, speak to your doctor.