Recognize, understand, and prevent vitamin deficiencies
ca. 14 Minuten
TL;DR:
- Many people in Switzerland suffer from vitamin D deficiency, especially in winter.
- Symptoms are often nonspecific, such as fatigue and difficulty concentrating.
- Blood tests are the most reliable way to identify a deficiency.
Fatigue that won't go away. Concentration that is declining. An immune system that is constantly weakened. Many people in Switzerland are familiar with these complaints, but rarely look for the cause where it often lies: vitamin deficiency. In fact, up to 34% of adults in Switzerland have low vitamin D levels, and in winter, over 80% have suboptimal levels. This article explains what causes vitamin deficiency, how to recognize the signs, and what steps you can take.
Table of contents
- The basics: What does vitamin deficiency actually mean?
- How can you recognize a vitamin deficiency? Typical signs and risk factors
- Diagnosis: How is vitamin deficiency reliably detected?
- Prevention: How can you prevent vitamin deficiencies?
- An honest look: Why vitamin deficiencies are often underestimated
- Your next steps toward better health
- Frequently asked questions
Key findings
| Point | Details |
|---|---|
| Vitamin deficiency is widespread | More than a third of Switzerland's population is affected by vitamin D deficiency. |
| Symptoms are often nonspecific | Problems such as fatigue or difficulty concentrating often go unrecognized. |
| Targeted diagnostics are essential | Only tests and professional assessment can reliably determine a deficiency. |
| Prevention is possible | With the right diet and supplements if needed, anyone can prevent a deficiency. |
| Get personalized advice | Professional health assessments support a sustainable supply of all vitamins. |
The basics: What does vitamin deficiency actually mean?
Vitamin deficiency sounds like a problem from times gone by. Scurvy among sailors, rickets among malnourished children. But anyone who thinks this is no longer an issue today is mistaken. In modern Switzerland, where grocery store shelves are full and meals seem plentiful, deficiencies in essential vitamins are surprisingly widespread. And they rarely appear dramatically, but instead develop gradually and often go unnoticed.
What exactly is vitamin deficiency? A vitamin deficiency occurs when the concentration of a particular vitamin in the body drops so low that bodily functions are impaired. Doctors distinguish between three states:
- Manifest deficiency: The vitamin level is so low that clear physical symptoms appear. For example, bone pain in cases of severe vitamin D deficiency or anemia in cases of extreme B12 deficiency.
- Latent deficiency: Lab values are below the optimal range, but there are no clinical symptoms yet. This condition is the most frequently overlooked, but it is harmful to health in the long term.
- Optimal supply: All markers are within the desired range, and the body can perform all functions fully.
“Most people who have a vitamin deficiency don't know it. Their levels are in the latent range; they don't feel really ill, but they don't feel quite well either.”
In Switzerland, two vitamins in particular are critical. Vitamin D deficiency is especially common because of the latitude and the long, cloudy winters. Vitamin B12 deficiency, in turn, primarily affects older adults and vegans, because B12 is found exclusively in animal products and its absorption in the gut requires a special protein called intrinsic factor. Without this protein, even a diet rich in B12 is of little use.
The symptoms of a vitamin deficiency can be so nonspecific that they are mistaken for stress, lack of sleep, or normal aging. That's exactly what makes early detection so difficult and so important. Anyone who wants to recognize vitamin D deficiency in time should not rely solely on how they feel.
How can you recognize a vitamin deficiency? Typical signs and risk factors
Now that we understand what a vitamin deficiency is, we can look at the specific signs and risk factors. The tricky thing about a deficiency is that its symptoms often resemble everyday complaints. Who hasn't gone through periods of feeling exhausted or sleeping poorly? This normality makes it so easy to overlook real warning signs.
Typical symptoms at a glance:
- Persistent fatigue and exhaustion despite getting enough sleep
- Concentration problems and mental sluggishness
- Muscle weakness or muscle cramps
- Low mood or lack of motivation
- Frequent colds and a weakened immune system
- Hair loss or brittle nails
- Tingling or numbness in the hands and feet (typical of B12 deficiency)
- Bone pain or an increased risk of fractures (typical of vitamin D deficiency)
What this list shows: Not one of these symptoms is specific. Fatigue can have a hundred causes. So can hair loss. That's why it's important to consider several symptoms together and not jump to the conclusion that it's stress or lack of sleep.
Table: An overview of the most important deficiencies
| Vitamin | Common symptoms | Main risk groups |
|---|---|---|
| Vitamin D | Fatigue, bone pain, frequent infections, low mood | All Swiss people in winter, people with little sun exposure, older adults |
| Vitamin B12 | Exhaustion, tingling, concentration problems, anemia | Vegans, older adults, people with gastrointestinal conditions |
| Folic acid | Anemia, exhaustion, memory problems | Pregnant women, women of childbearing age, people who consume alcohol |
| Vitamin C | Frequent infections, poor wound healing, bleeding gums | Smokers, people with an unbalanced diet |
| Iron (not a vitamin, but often deficient at the same time) | Fatigue, paleness, rapid heartbeat | Women, vegans, athletes |
According to current data, 21 to 41% of adults in Switzerland are particularly at risk of B12 deficiency, including older people and vegans in particular. These figures surprise many people, because B12 is not considered an “exotic” vitamin. But the body cannot produce it itself, and absorption in the gut is impaired in many people.
For a comprehensive overview of all possible symptoms of vitamin deficiency, it’s worth learning about the different patterns. For example, knowing the typical vitamin B12 deficiency symptoms can help you recognize warning signs earlier and take targeted action. The causes of vitamin B12 deficiency range from an improper diet to diseases of the digestive tract.
Pro tip: Don’t focus on individual symptoms, but on patterns. If fatigue, concentration problems, and a weakened immune system occur at the same time, that is a stronger signal than any symptom on its own.
Diagnosis: How is vitamin deficiency reliably detected?
After considering the symptoms, the crucial question is: How can you check your vitamin status accurately and reliably? Symptoms alone are not enough. Fatigue can also indicate thyroid problems, iron deficiency, or depression. Only a test provides certainty.
The blood test as the gold standard
The most direct way to diagnose a deficiency is with a blood test. The laboratory measures blood levels of specific vitamins, such as 25-OH vitamin D for vitamin D or holotranscobalamin for vitamin B12. These levels show whether there is a deficiency. The problem in Switzerland: Since 2022, health insurers have only reimbursed blood tests to a limited extent, especially for vitamin D and B12. Many people have to pay the costs themselves, which discourages them from finding out their status at all.
Functional markers as a complementary method
A regular blood test shows how much vitamin is present in the blood. But whether the body can actually use this vitamin is another question. This is where so-called functional markers help. Methylmalonic acid (MMA) is one such marker for vitamin B12. Elevated MMA levels in the blood or urine indicate that the body cannot use B12 adequately, even if the B12 level itself is still borderline. This makes MMA a more sensitive early warning sign.
Step-by-step self-diagnosis:
- Document symptoms: Write down which symptoms occur and how often over two to four weeks. Patterns are more informative than individual bad days.
- Check risk factors: Are you vegan, over 60, work mostly indoors, or live in a country with few hours of sunshine? These factors significantly increase your risk.
- Use a self-test: High-quality self-tests for vitamin deficiencies make it easy to collect a blood sample at home. The sample is sent to a certified lab, and the results are delivered via an app or report.
- Interpret results correctly: Lab results have reference ranges, but “within the normal range” does not automatically mean “optimal.” Always have an expert interpret your results.
- Take targeted action: Targeted supplementation or dietary changes only make sense once it is clear which vitamins are actually lacking.
Anyone who wants to know their status precisely can use mybody® to test for specific nutrient deficiencies and rely on lab-tested quality. Precise methods are now available, especially for measuring vitamin B12 deficiency, going far beyond a simple estimate.
Pro tip: Borderline lab results don’t mean everything is fine. A value at the lower end of the normal range combined with relevant symptoms is a finding that should be taken seriously. Always have a specialist review your results, not just the chart on the lab report.
Prevention: How can you prevent vitamin deficiencies?
If a deficiency has been identified or there is an increased risk, prevention is the most important next step. Even those who currently have no symptoms can benefit in the long term from smart preventive care. The body stores some vitamins, while others need to be replenished daily. This makes the strategy individual.
What really helps, concrete and practical:
- Promote vitamin D synthesis: 15 to 30 minutes of midday sun on your arms and face every day, from April to October, is enough for many people. In winter, this hardly works in Switzerland.
- Boost vitamin B12 sources: Meat, fish, eggs, and dairy products provide B12. Vegans need to use supplements or fortified foods, as plant-based sources do not contain a form the body can use.
- Make use of seasonal foods: Fresh, locally grown fruits and vegetables contain more vitamins than imported produce that has been transported for weeks.
- Recognize high-risk periods: Winter, pregnancy, breastfeeding, chronic illnesses, and intensive exercise increase vitamin requirements. During these periods, the body needs more.
- No blind supplementation: Simply taking supplements without test results risks overdosing. Vitamins A and D are fat-soluble and can build up in the body if taken in excess.
Comparison: Natural intake versus supplementation
| Criterion | Natural intake through diet | Targeted supplementation |
|---|---|---|
| Bioavailability | Often optimal, since vitamins are absorbed along with other nutrients | Varies considerably depending on the supplement and form |
| Dosage control | Difficult, as levels in foods vary | Can be precise when based on test results |
| Risk of overdose | Very low with a normal diet | Possible, especially with fat-soluble vitamins |
| Cost | Usually less expensive | Can become costly without targeted use |
| Ease of fitting into daily life | Requires planning and knowledge of food sources | Simple and time-saving |
| Recommendation | Foundation for everyone | Useful for a confirmed deficiency or increased risk |
Specific recommendations apply in Switzerland: During winter, 800 international units of vitamin D daily are recommended as a supplement for at-risk groups. Vegans should always supplement with B12. For practical guidance on dietary choices, vitamin B12 in the diet offers helpful information about which foods are genuine sources and which only sound good on paper.
A well-considered strategy for preventing nutrient deficiencies always combines several approaches: a good diet as the foundation, targeted supplementation when a need has been confirmed, and regular monitoring of your levels.
Pro tip: If you’re in a risk group, such as being vegan, over 60, or spending little time outdoors in winter, you shouldn’t have your vitamin levels tested just once. Checking every three to six months gives you peace of mind and helps you take action early, before symptoms appear.
An honest look: Why vitamin deficiencies are often underestimated
There’s an uncomfortable truth that many don’t want to hear: Even people who eat mindfully, have salad every day, eat little meat, and take care of their health can have a vitamin deficiency. A good diet alone is no guarantee.
Why? Because many factors come into play that have nothing to do with the quality of your food. Switzerland’s geographic latitude, for example. From October to April, the sun simply isn’t strong enough for the skin to synthesize sufficient vitamin D. That’s physics, not a matter of lifestyle. Even people who go for a walk every day don’t get enough without adequate supplementation in winter. The high prevalence of vitamin D deficiency in Switzerland isn’t an individual failing, but a geographic reality.
There’s another pitfall, too: feeling that you’d already know if something were wrong. This thought is tempting, but it’s mistaken. The body compensates for a latent deficiency for a long time before symptoms appear. It’s a master at compensating. By the time symptoms arise, a deficiency may have been present for months or years. Waiting for obvious symptoms is therefore not a good strategy.
Something we keep noticing at mybody®: People who feel healthy are sometimes the most surprised when their test results show that their vitamin D, B12, or other nutrient levels aren’t optimal. Subjective well-being and objective vitamin status often don’t align. That’s exactly why individual testing is so valuable. It replaces gut feeling with facts.
Another misconception is the assumption that supplementation is always the answer. If you take capsules on a whim without testing, you’re not optimizing anything. Too much vitamin A can damage the liver. Too much vitamin D raises blood calcium to a dangerous level. And if you’re getting too little of a particular vitamin that you aren’t supplementing, you’re still getting too little. Only when you know your status can you take targeted action.
The solution isn’t panic, but clarity. If you know your vitamin status and where you stand, you can make informed decisions. And today, that’s easier than ever. Nutrient deficiencies can be addressed with targeted measures once you know whether and where they exist. The first step is always testing.
We believe that preventive health testing isn’t a luxury but one of the smartest investments you can make in yourself. Recognizing early where your body needs support helps you stay healthier, more energetic, and free from discomfort in the long term. That’s not a promise; it’s biology.
Your next steps toward better health
You now know that vitamin deficiencies are widespread in Switzerland, often go undetected, and affect health even when levels are only borderline. This knowledge is valuable. But knowledge alone is not enough. What matters is the next concrete step.
At mybody®, you can conveniently test your vitamin levels from home. ISO-certified laboratory analyses of small blood samples that you collect yourself provide you with a personalized report with precise results, clear interpretations, and individual dietary recommendations. No waiting for a doctor's appointment. No uncertainty about what health insurance covers. Just reliable data you can act on. More than 11,300 customers have already chosen this approach and sustainably improved their health. Become one of them.
Frequently asked questions
Why is vitamin D deficiency so widespread in Switzerland?
Because of its geographical location and the limited hours of sunshine in winter, many people in Switzerland have low vitamin D levels. Up to 34% of adults are below the recommended threshold, and more than 80% have suboptimal levels in winter.
What symptoms indicate a vitamin deficiency?
Typical symptoms include fatigue, difficulty concentrating, muscle weakness, or low mood. Several of these symptoms occurring at once should raise concern, as a single symptom alone is rarely conclusive.
Are blood tests to detect vitamin deficiencies covered by health insurance in Switzerland?
Since 2022, health insurance companies have only covered blood tests to a limited extent. Many people have to pay for tests themselves, especially for vitamin D and B12. Affordable home tests are a practical alternative.
How can I best prevent a vitamin deficiency?
A varied diet, sufficient exercise outdoors, and targeted supplementation when needed are key. Experts recommend that at-risk groups take 800 IU of vitamin D daily in winter, and that vegans take B12 as a long-term supplement.
Are vegans or older people particularly at risk?
Yes, older people and vegans in particular often have a vitamin B12 deficiency. 21 to 41% of adults are affected, and these groups should have their levels checked regularly and specifically.
Recommendation
- Recognizing vitamin deficiencies and taking individual action – mybody®x
- Recognizing nutrient deficiency symptoms and taking targeted action – mybody®x
- Recognizing vitamin B12 deficiency symptoms and taking the right steps – mybody®x
- Recognizing and sustainably correcting vitamin B12 deficiency – mybody®x
- Vitamin D Deficiency Symptoms: Recognize the Signs in Time – Vitaminone.dk
