Which supplements should you take to general health?

The minimum you can defend with sources is omega 3 and vitamin d, which at the dose used in the studies comes to €1.22 a month buying the cheapest that reaches that dose. Beyond that, this page lists another 5 with evidence behind them, each for a specific case.

Multivitamins has weak evidence for this: Reviews find no consistent effect. It is listed because it sells, not because it works. They are sold a lot for this goal and each has its own guide with the sources, so the decision does not depend on what a label says.

Where do these prices come from?

From the 4065 products this site collects across 19 Spanish stores, with prices from October 15, 2026. The monthly cost is one effective dose a day for 30 days, with the cheapest product that reaches that dose. The evidence was reviewed on September 4, 2026.

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By goal · evidence reviewed on September 4, 2026

Which supplements make sense for general health

The short answer. What holds up with sources is short: omega 3 and vitamin d, about €1.22 a month at the dose used in the studies. This page lists 7 supplements with evidence for this goal, and 1 sold for it that you do not need.

No deficiency, no effect: a supplement here only does something if it fills a gap left open by diet or sunlight. That is why the ones that make sense are few and very specific.

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The basics, and what they cost

Strong evidence

Omega 3

€1.22a month

250 mg a day of EPA+DHA combined as a general reference. Uses at 2-3 g are something else and have a doctor behind them.

Cheapest at that dose: Mensan Omega 3 660 Mg 220 Perlas from Bulevip, €0.041/capsule.

Moderate evidence

Vitamin D

—a month

Whatever your blood test calls for. Common presentations range from 1000 to 4000 IU.

€1.22 a month in total, adding up omega 3 at one effective dose a day with the cheapest product that reaches that dose. It is not a medical recommendation or a plan: it is what the evidence-backed options cost today, in the stores this site compares.

The 7 with something behind them

By evidence level and monthly cost

Supplements with evidence for: general health
Supplement	Evidence	What has been measured	Per month
Omega 3250 mg a day of EPA+DHA combined as a general reference. Uses at 2-3 g are something else and have a doctor behind them.	Strong evidence152 products compared · best score: Mensan Omega 3 660 Mg 220 Perlas from Bulevip	Blood triglycerides: -20 to -30 %EFSA Panel on Dietetic Products, Nutrition and Allergies. Scientific Opinion on Dietary Reference Values for fats. EFSA Journal. 2010;8(3):1461. Ingesta adecuada de 250 mg diarios de EPA+DHA.	€1.22
Vitamin C80 mg covers the reference value; common presentations range from 500 to 1000 mg.	Strong evidence127 products compared · best score: Vitamina C 1000mg - 365 cápsulas - Suave para el estómago y sin ácido - Refuerza el sistema inmunitario y el metabolismo energético - Probado en laboratorio from Amazon	Functions authorised in the EU: collagen, immunity, iron and tirednessReglamento (UE) 1169/2011, Anexo XIII: valores de referencia de nutrientes. Vitamina C, 80 mg.	€1.65
Vitamin B12On a vegan diet, the usual approach is a high weekly dose or a smaller daily one. Adjust it with whoever manages your case.	Strong evidence106 products compared · best score: Vitamina B12 500 µg con Ácido Fólico – 400 Comprimidos from Amazon	Functions authorised in the EU: red blood cells, energy and tirednessReglamento (UE) 1169/2011, Anexo XIII: valores de referencia de nutrientes. Vitamina B12, 2,5 microgramos.	no published dose
ZincAround the 10 mg reference value, counting what the diet already provides.	Moderate evidence81 products compared · best score: Vitaminalia Gluconato de zinc (25mg zinc) 365 tabletas from HSN	Functions authorised in the EU: immunity, cells and normal testosteroneReglamento (UE) 1169/2011, Anexo XIII: valores de referencia de nutrientes. Zinc, 10 mg.	€2.87
IronWhatever the person who has seen your blood test says. The labelling reference value is 14 mg.	Moderate evidence101 products compared · best score: Zumub Hierro 200 comprimidos (2x 100) from Zumub	Functions authorised in the EU: red blood cells, oxygen and tirednessReglamento (UE) 1169/2011, Anexo XIII: valores de referencia de nutrientes. Hierro, 14 mg.	€5.99
Vitamin DWhatever your blood test calls for. Common presentations range from 1000 to 4000 IU.	Moderate evidence137 products compared · best score: Vitamina D3-4000 UI – Alta Concentración – Cura de 6 Meses \| Defensas - Inmunidad y Salud Ósea - 365 Comprimidos - Bienestar Diario Para Todo El Año Con Vitaminas y Minerales - Vitavea from Amazon	Functions authorised in the EU: bones, muscle and immunityReglamento (UE) 1169/2011, Anexo XIII: valores de referencia de nutrientes. Vitamina D, 5 microgramos.	no published dose
ProbioticsThe one from that strain’s trial. In general, between one billion and one hundred billion CFU a day.	Moderate evidence107 products compared · best score: Sotya Carbón Activado con Probióticos 90caps from PromoFarma	What matters: the strain, not the genusJager R et al. ISSN position stand: Probiotics. J Int Soc Sports Nutr. 2019;16:62. Los efectos son especificos de cepa; dosis habituales de 10^9 a 10^11 UFC al dia.	no published dose

The 1 they will try to sell you for this

Weak evidence, supplement price

Reviews find no consistent effect. It is listed because it sells, not because it works.

Weak-evidence supplements sold for: general health
Supplement	What has been measured	Per month
MultivitaminsA multivitamin corrects deficiencies; it does not improve the performance of people who do not have them.	Performance in people without deficiencies: no effectKerksick CM et al. ISSN exercise & sports nutrition review update: research & recommendations. J Int Soc Sports Nutr. 2018;15:38. Los micronutrientes solo mejoran el rendimiento cuando corrigen un deficit previo.	no published dose

Weak evidence is not fraud. It means the effect does not show up when diet already fills the gap, or that the studies behind it are small, short or paid for by the seller. Each guide says in which specific case it does make sense, which almost always exists and is almost never the case of the person buying it.

Questions about supplements for: general health

Answered with the data on this page

Which supplements should you take to general health?: The minimum you can defend with sources is omega 3 and vitamin d, which at the dose used in the studies comes to €1.22 a month buying the cheapest that reaches that dose. Beyond that, this page lists another 5 with evidence behind them, each for a specific case.
And multivitamins?: Multivitamins has weak evidence for this: Reviews find no consistent effect. It is listed because it sells, not because it works. They are sold a lot for this goal and each has its own guide with the sources, so the decision does not depend on what a label says.
Where do these prices come from?: From the 4065 products this site collects across 19 Spanish stores, with prices from October 15, 2026. The monthly cost is one effective dose a day for 30 days, with the cheapest product that reaches that dose. The evidence was reviewed on September 4, 2026.

Other goals

The same list, another question

Build muscle7 supplements Lose fat4 supplements Performance and strength6 supplements Joints4 supplements Sleep and stress3 supplements All of them, by evidence50 guides