Micronutrients — what your body actually needs

Micronutrients are vitamins, minerals, and trace elements that your body can't produce on its own and therefore has to take in via food. Unlike macronutrients — protein, fat, carbohydrates — they don't supply energy. But they make the difference between the energy in your lunch actually reaching muscles, nerve cells, and metabolism, and getting stuck halfway.

This article is the overview. There's a dedicated piece for each individual topic — we link them at the appropriate spots.

What micronutrients are and what they're for

Micronutrients are functionally an extremely heterogeneous group. Some are directly involved in producing energy (B vitamins, magnesium), others ensure oxygen transport (iron), still others support the immune system (vitamin D in winter) or heart function (omega-3).

What they share: they work in tiny amounts — micrograms or milligrams per day, not grams — and they work together. Looking at a single micronutrient in isolation almost always misses the picture. Iron, vitamin B12, and folate, for instance, work hand in hand in blood formation. Magnesium and vitamin D jointly support muscle and bone function.

Which micronutrients are particularly relevant in everyday German life

The National Nutrition Survey II from BMEL has measured where average intake in Germany actually falls below the DGE estimated value. A few topics keep coming up:

Nutrient	Frequent shortfall in	Daily intake (adults)
Vitamin D	almost everyone in winter, older people	20 µg (estimated value)
Iron	women before menopause, vegan diet	11 mg (m) / 16 mg (w premenopausal)
Folate (B9)	broadly distributed	300 µg folate equivalents
Vitamin B12	strictly plant-based diet, older people	4 µg
Magnesium	athletes, one-sided diet	350 mg (m) / 300 mg (w)
Omega-3 (EPA/DHA)	low or no fatty sea fish	250 mg EPA+DHA for heart function

The values are DGE reference values, 2023 (iron) or 2021 (magnesium). For pregnancy, breastfeeding, adolescents, and older people, partly different recommendations apply — the dedicated articles list them in detail.

When supplementation makes sense — and when it doesn't

The DGE explicitly does not recommend multivitamin products as a default solution. A balanced diet with whole grains, legumes, vegetables, fruit, and occasional fish or meat covers most needs cleanly.

Targeted supplementation makes sense in a few clearly defined cases:

• Vitamin D in winter: own synthesis from October to March is practically impossible in Germany — moderate supplementation in these months is one of the few generally defensible recommendations.
• Vitamin B12 on a strictly plant-based diet: plant foods practically don't deliver any usable B12. Here supplementation is routine, not up for debate.
• Iron, folate, magnesium with a medically established deficiency or documented increased need (pregnancy, intense sport, heavy menstruation).
• Omega-3 (EPA/DHA) with little or no fish intake: algae oil is the vegan-friendly alternative to fish oil.

What does not make sense: high-dose multi products "on a hunch". For most micronutrients, oversupply is just as problematic as undersupply — for some (iron, B6) clearly more so.

What you'll see on labels in legal terms

Statements about the action of micronutrients are tightly regulated in the EU. Only claims listed in EU Regulation 432/2012 and scientifically validated by EFSA are allowed. Examples:

• "Magnesium contributes to normal muscle function"
• "Iron contributes to the reduction of tiredness and fatigue"
• "Vitamin D contributes to the normal function of the immune system"

What you won't see on labels — and what's marketing-speak: vague immune promises, generic statements about concentration, or the big promise of more energy and quality of life without a concrete nutrient reference. Such phrasings are either not permitted at all or only in tightly defined form. Anyone seeing them on packaging should be skeptical — the CJEU ruling C-386/23 (2025) has further tightened the line for plant-based ingredients.

Bioavailability in brief

How much of a nutrient actually ends up in the body doesn't only depend on the amount on the plate or in the tablet. Three factors usually make the difference:

• Chemical form: magnesium citrate, for example, is absorbed better than magnesium oxide. Iron from meat (heme) at 15–35%, iron from plants (non-heme) at 2–20%.
• Meal context: vitamin C with plant iron — clearly improves uptake. Coffee and black tea with the iron meal — inhibit it. Fat-soluble vitamins (A, D, E, K) need a bit of fat in the meal.
• Individual factors: stomach acid, gut health, age, medications. Proton pump inhibitors, for instance, reduce B12 uptake noticeably.

Concretely: two people eating the same don't necessarily end up with the same supply. That's exactly why blanket recommendations are limited in usefulness — and exactly why the dedicated articles look at individual nutrients more closely.

If you want to know where you stand

A real assessment of your supply runs through a blood test at your GP — hemoglobin, ferritin, vitamin D, B12 are the most common markers. Self-diagnosis via symptoms is unreliable: fatigue, for example, can come from iron, B12, folate, vitamin D, magnesium, or simply lack of sleep. The GP sorts that out.

For a first low-threshold orientation — not medical, but honest — there's the free Vital-Check. Three minutes of questionnaire, then you get a written assessment of which micronutrients may play a role in your daily life and where an adjustment can make sense. The flow is described in How a Vital-Check works. For clear or persistent complaints, however, medical clarification is and stays the right address.

The dedicated articles at a glance

If you want to dive deeper, here are the topic articles:

• Magnesium and muscle function — daily intake, absorption forms, when extra needs apply
• Vitamin D in winter — own synthesis, estimated value, sensible supplementation
• Iron and tiredness — heme vs. non-heme iron, when to consult a doctor
• Omega-3 for heart function — EPA, DHA, ALA and the difference
• B vitamins overview — B12, B6, folate, and their roles
• Amino acids and sport — BCAA, EAA, protein needs per DGE
• Antioxidants and cell protection — vitamin C, E, selenium, zinc and free radicals
• Bioavailability explained — what actually shapes uptake in everyday life
• Skincare from within — biotin, zinc, vitamin C, and what the EFSA permits for skin
• Micronutrients after 50 — B12, vitamin D, calcium, and what shifts