Vitamin D: Why We Need It and How to Avoid Deficiency in Winter

Vitamin D is called the "sunshine vitamin" because its primary source is sunlight. It is thanks to UVB rays that our body can manufacture it on its own. Unfortunately, during the autumn and winter period, when days are shorter and there is less sunlight, the production of vitamin D drops significantly. That is why so many people in Poland struggle with its deficiency, which can have a serious impact on health.

1. Why vitamin D is so important

Vitamin D performs many crucial functions in the body. It is responsible for the proper absorption of calcium and phosphorus, thereby strengthening bones and teeth. It also supports the operation of the immune system, helps maintain proper blood sugar levels, and favorably affects well-being. An increasing number of studies confirm that an adequate level of it can reduce the risk of infections, seasonal depression, and even certain heart diseases.

2. Symptoms of vitamin D deficiency

Vitamin D deficiency often develops slowly and shows no clear symptoms for a long time. Over time, however, the following may appear:

• weakness and fatigue,
• muscle and joint pain,
• lowered mood, irritability,
• more frequent infections,
• concentration problems.

In children, deficiency can lead to rickets, and in adults to osteoporosis and lowered immunity.

3. Where to get vitamin D

The best source of vitamin D is the sun – about 15–20 minutes of exposure daily in the summer months is enough to replenish reserves. Unfortunately, from October to March, UVB radiation in Poland is too weak for the body to produce a sufficient amount of this vitamin on its own.

Therefore, in winter it is worth reaching for products rich in vitamin D, such as:

• fatty sea fish (salmon, mackerel, herring, sardines),
• eggs,
• dairy products,
• liver,
• vegetable oils.

4. Supplementation – when is it needed

In the autumn and winter period, vitamin D supplementation is often necessary. Before reaching for supplements, however, it is worth checking the 25(OH)D level in your blood and consulting the dosage with a doctor. A typical preventive dose for adults is 1000–2000 IU daily, but it may vary depending on age, body weight, and lifestyle.

Recommended amounts should not be exceeded – an excess of vitamin D can also be harmful. It manifests, among other things, as nausea, weakness, and heart rhythm disorders.

5. How to support the absorption of vitamin D

Vitamin D is fat-soluble, which is why it is best taken during a meal containing healthy fats (e.g. olive oil or avocado). It works well in combination with magnesium, vitamin K2, and zinc, which support its metabolism and absorption.

Summary

Vitamin D is an essential nutrient that affects immunity, the skeletal system, and overall well-being. In Poland, due to the climate, its deficiencies are very common – especially in winter. It is therefore worth remembering to maintain a healthy diet, go for walks in the fresh air, and supplement during the autumn-winter period. Thanks to this, the body will remain strong, and immunity – reliable all year round.