Doctoral defence: Leho Rips "The influence of vitamin D on the physical performance of conscripts in the Estonian Defence Forces"

On December 6th Leho Rips will defend his thesis "The influence of vitamin D on the physical performance of conscripts in the Estonian Defence Forces". 

Supervisors: 
Lecturer Madis Rahu, University of Tartu
Professor Jüri-Toomas Kartus, University of Gothenburg (Sweden)
Doctor Alar Toom, Central Finland Central Hospital (Finland)
Doctor Mart Kull, Viljandi Hospital

Opponent: 
Professor Adad Baranto, University of Gothenburg (Sweden)

Summary:
D vitamins – calciferols - are a group of fat-soluble vitamins that behave similarly to hormones in the human body. The most well-known forms of vitamin D are animal-derived vitamin D3 (cholecalciferol) and plant-derived vitamin D2 (ergocalciferol). Approximately 90% of the vitamin D in the human body is produced on the surface of the skin by the action of ultraviolet radiation, 10–20% is of animal origin, and only about 1% comes from plants. Supplementation in the form of capsules or oil is also used to prevent vitamin D deficiency. Vitamin D is assessed indirectly by determining blood serum 25(OH)D levels in the human body. Vitamin D deficiency is a very widespread problem, but it still often comes as a surprise, because even a long-term deficiency does not cause noticeable physical effects in most people. 

Vitamin D is very important in bone metabolism, and in conditions of deficiency, the risk of osteopenia and osteoporosis, bone fractures, stress fractures, and immune system dysfunction increases, and there is a reduction in physical work capacity. The risk of vitamin D deficiency occurs in all age groups and increases in occupations involving very high physical and mental stress, which includes military service. Physical fitness is critical in the military for both training and missions. Research shows conflicting associations between physical performance and vitamin D deficiency.

The aim of this study was to evaluate the levels of vitamin D in different seasons, the effect of supplementation, and the relationship with physical performance in Estonian conscripts.

During the research, we found that there was already a vitamin D deficiency in the summer months which then tends to be worst by spring. Long-term vitamin D supplementation in low doses (up to 1200 IU) did not increase serum 25(OH)D, unlike the administration of 4000 IU, for which the effect was positive. In physical performance tests conducted during the same study, no correlations between vitamin D deficiency and physical capacity were found in the study groups.

As a result of the doctoral thesis, we can give new recommendations for the prevention of vitamin D deficiency in young men.

You can watch defense via Teams.