Vitamin D3 is a vital vitamin involved in numerous metabolic processes and supports our well-being in various ways. It promotes mental health, prevents rickets in infants, and stabilizes bones. The human body can produce Vitamin D3 through the skin. However, since sunlight is often insufficient – especially during the winter months – a deficiency is common in this country.
What are the functions of Vitamin D3?
Vitamin D3 (cholecalciferol) is not actually a vitamin, but the bioactive form of the prohormone Vitamin D. It plays a crucial role in calcium metabolism and is essential for the building and maintenance of strong bones and teeth.
Vitamin D3 supports the absorption of calcium and phosphate from the intestine, increases bone mineralization, and can specifically prevent osteoporosis. Furthermore, Vitamin D3 strengthens the immune system: adequate supply is important for the body to mobilize effective defense cells during infections.
Vitamin D3 Deficiency: Causes & Symptoms
Approximately 80% of the body's own Vitamin D3 is produced through sun exposure to the skin. In summer, self-production can be almost complete, but not in winter months. A Vitamin D3 deficiency can manifest through the following symptoms:
Fatigue and exhaustion
Muscle weakness or bone pain
Increased susceptibility to infection
Depressive moods
Long-term: osteoporosis or bone softening (osteomalacia)
Studies also show a correlation between Vitamin D3 deficiency and depression. People with insufficient supply suffer significantly more often from depressive disorders.
Use of Vitamin D3
An adequate supply of Vitamin D3 is important all year round – not only for calcium metabolism, but also for immune defenses and general well-being.
The intake of Vitamin D3 capsules or Vitamin D3 tablets is particularly useful for:
Too little sunlight (winter, bedridden, clothing, dark complexion)
Increased stress in old age or during menopause
Diseases such as celiac disease, Crohn's disease or nephrotic syndrome
Taking certain medications (e.g. antiepileptics)
Those who want to supplement their diet specifically should use high-quality Vitamin D3 supplements.
Which foods contain Vitamin D3?
Cod liver oil and fish oil are particularly rich in Vitamin D3. Fish and seafood such as eel, salmon, herring, and mussels also contain large quantities. Porcini mushrooms, chanterelles, and button mushrooms also provide relevant amounts. Nevertheless, diet alone is often not enough to cover daily needs.
Am I deficient in Vitamin D3?
If one or more of the following points apply to you, your supply of Vitamin D3 may be insufficient. In these cases, taking Vitamin D3 tablets or Vitamin D3 capsules is recommended:
You are rarely in the sun or mostly heavily clothed
You often feel tired and exhausted after winter
You eat an almost exclusively plant-based or very one-sided diet
You are older or have a dark complexion
You regularly take antiepileptic drugs
You suffer from chronic intestinal diseases
What should I consider when taking Vitamin D3?
An overdose only occurs with extremely high amounts (over 40,000 IU = 1,000 µg per day). Too much Vitamin D3 can lead to hypercalcemia (excessive calcium absorption) or hypercalciuria (increased calcium excretion).
Important: When taking larger amounts of Vitamin D3, it is important to ensure an adequate supply of Vitamin K2 at the same time to avoid a functional K2 deficiency.
