The Sunshine Vitamin Most People Lack
Vitamin D deficiency is one of the most common nutritional deficiencies I diagnose in my practice in Zürich Seefeld. In Switzerland, up to 60% of the population has suboptimal vitamin D levels during winter months. The consequences go far beyond bone health – vitamin D influences our immune system, mood, energy levels, and much more.
Symptoms of Vitamin D Deficiency
The symptoms are often subtle and develop gradually: persistent fatigue and low energy, frequent infections and slow recovery, depressive mood especially in winter, muscle weakness and pain, bone pain and increased fracture risk, hair loss, difficulty concentrating, and sleep disturbances. Many patients attribute these symptoms to stress or aging – but the real cause may be a simple vitamin deficiency.
Why Deficiency Is So Common
1. Insufficient sun exposure: In Switzerland, the sun is too weak from October to April to produce adequate vitamin D. Office workers, elderly people, and those with darker skin are particularly at risk. What we do: Measure 25-OH-vitamin D levels and supplement based on results.
2. Limited dietary sources: Few foods contain significant amounts of vitamin D – fatty fish, egg yolks, and mushrooms provide some, but rarely enough. What we do: Individual dietary assessment and supplementation guidance.
3. Impaired absorption: Gut problems such as celiac disease, Crohn’s disease, or general dysbiosis can reduce vitamin D absorption. Obesity also lowers bioavailability as vitamin D is stored in fat tissue. What we do: Comprehensive gut assessment when vitamin D levels remain low despite supplementation.
Optimal Levels
The standard reference range considers anything above 20 ng/ml as “sufficient.” In functional medicine, we aim higher: 40–60 ng/ml is our target range for optimal health. At these levels, the immune-modulating and mood-enhancing effects of vitamin D are most pronounced.
Diagnosis and Treatment
A simple blood test (25-OH-vitamin D) reveals your status. If deficient, we recommend high-dose supplementation (typically 2,000–5,000 IU daily) along with vitamin K2 to ensure proper calcium metabolism. We recheck levels after 3 months and adjust the dose accordingly. Maintenance supplementation during winter is usually advisable for everyone in Switzerland.
Conclusion
Vitamin D deficiency is extremely common, easy to diagnose, and simple to treat. If you experience any of the symptoms described above, schedule an appointment at our practice – a blood test can provide clarity within days.
