Even at the end of the summer season, one third of Estonians have too little vitamin D in their bodies.
According to the doctoral thesis which Mart Kull defended at the University of Tartu’s Faculty of Medicine, this is most severe during the winter, when 73% of the Estonian population has less vitamin D than required and 8% suffers from complete vitamin deficiency.
A study carried out at the University of Tartu Internal Medicine Clinic collected data from nearly 400 healthy persons, aged 25-70, from all over Estonia.
“Such a large-scale vitamin D deficiency in Estonia is surprising, as the situation in the neighbouring northern countries is better,” said Kull.
Dairy products fortified with vitamin D, which partly compensate for the vitamin deficiency caused by the lack of sunshine during winters, have been available in Finland, Sweden, Norway and USA for years.
None of the Baltic countries are currently fortifying food with vitamin D. It is available as a food supplement from pharmacies, but practically none of the people who participated in the survey were using supplements containing vitamin D.
Another source of vitamin D is fish, but fish is not a very popular food in Estonia.
Eight months without the sun
Vitamin D is produced mainly in the human skin cells by sunlight. It’s often claimed that there is no need to sunbathe in order to get the vitamin – just spending a quarter of an hour outdoors with your face and hands uncovered should provide the daily dose.
“This is sufficient during the four summer months of the year, but UV-radiation measurements performed by University of Tartu physicists show that from October until the beginning of May the sunshine is not intense enough to produce vitamin D in the skin,” explained Kull.
Therefore, in addition to the daily supply of vitamin D, one should also acquire “winter supplies” during the summer – this increases vitamin reserves by several months’ worth. Even these, however, are exhausted by late autumn. During the winter, we really need an additional source of vitamin D.
“Things are better for Estonians who have visited warmer countries during colder and darker seasons. The survey indicated that these people had enough vitamin D even during the winter. Unfortunately, few of us have such an opportunity” said Kull.
Vitamin D deficiency is a risk factor
Vitamin D is extremely important when it comes to skeletal health. In recent years, there have been articles published around the world showing how the insufficient level of vitamin D in the human body plays a huge part in the development of many different diseases. The vitamin regulates the activity of at least 200 of our genes.
Vitamin D deficiency has been linked to a higher frequency of various cancers and also to cardiovascular and autoimmune diseases.
The survey performed at the Internal Medicine Clinic showed that overweight and older Estonians are an important risk group. A comparison of sunbathing habits showed that overweight and elderly people usually get less sunlight.
“It definitely doesn’t mean that Estonians should spend all their free time under the sun during the summer, because too much UV radiation leads to cancer. But it seems that the benefits of modest and protected sunbathing far outweigh the health risks involved with sunbathing in general. Many studies performed all around the world have shown that,” asserted Kull.