Vitamin D is a vital nutrient that is essential for the body's overall health and well-being. It plays a crucial role in maintaining strong bones and teeth by aiding in the absorption of calcium and phosphorus from the diet. Besides its role in bone health, vitamin D also supports the proper functioning of the immune system, helps regulate insulin levels, and promotes muscle strength. It is even believed to have a positive effect on mood and mental health.

The main sources of vitamin D are:

• Sunlight: This is the primary source of vitamin D for most people, as the skin can synthesize vitamin D from exposure to ultraviolet B (UVB) rays. However, the formation of vitamin D in the skin is influenced by various factors (including the use of sunscreen) and is usually insufficient in Switzerland. Sunlight exposure also carries the risk of skin damage and cancer, so it is important to balance the benefits and harms of sun exposure.
• Food: Fatty fish is among the best food sources of vitamin D3. Examples include salmon, sardines, herring, mackerel, and trout.¹³ In order to achieve a sufficient intake of vitamin D through food, 2 servings of oily fish would have to be taken daily. Mushrooms can provide variable amounts of vitamin D2. However, the amount and type of vitamin D2 in mushrooms vary depending on the species, growing conditions, and processing methods⁴.
• Dietary supplements: These can contain either vitamin D2 or vitamin D3. Vitamin D2 is derived from yeast or mushrooms, while vitamin D3 in supplements is typically derived from lanolin (the coating of sheep's wool) or fish oil ¹. There are also vegan Vitamin D3 supplements, which use lichen or algae as sources of vitamin D3. Both forms of vitamin D can raise serum 25-hydroxyvitamin D levels, but vitamin D3 is more potent and longer-lasting than vitamin D2.

Yes, vitamin D deficiency is a significant issue in Switzerland. Approximately 40-50% of the population is estimated to be deficient in vitamin D. Elderly individuals in Switzerland are particularly affected, with an 80% deficiency rate. According to the Federal Office of Public Health (BAG), during winter around 60% of the total Swiss population has an insufficient supply of vitamin D.

Symptoms of vitamin D deficiency can be subtle and may not manifest for months or even years. In some cases, there may be no noticeable symptoms at all. However, common signs of deficiency include frequent illnesses or infections, fatigue, back pain, hair loss, poor wound healing, and symptoms of depression. If you suspect a vitamin D deficiency, it is advisable to consult with your family doctor for proper evaluation.

The recommended daily intake of vitamin D varies depending on various factors and it is best to consult with a family doctor for personalized recommendations. In Switzerland, the nutrient reference values suggest that healthy men and women should aim for 15 to 20 μg (600-800 IU) of vitamin D per day from food, supplements, and endogenous production. The upper safe intake level is considered to be 100 μg (4000 IU) per day.

Vitamin D supplements are available in various locations throughout Switzerland. Pharmacies and drugstores are common places to buy them. Additionally, health food stores, supermarkets, and online retailers offer a wide range of options. At Vitamister, a Swiss online drugstore for Healthy Families, we also provide a wide range of vitamin D3 supplements in different dosage forms and dosage levels to cater to your specific needs.