Direct Effects of Vitamin D Supplementation on Ultramarathon-Induced Changes in Kynurenine Metabolism.

In humans, most free tryptophan is degraded via kynurenine pathways into kynurenines. Kynurenines modulate the immune system, central nervous system, and skeletal muscle bioenergetics. Consequently, kynurenine pathway metabolites (KPMs) have been studied in the context of exercise. However, the effect of vitamin D supplementation on exercise-induced changes in KPMs has not been investigated. Here, we analyzed the effect of a single high-dose vitamin D supplementation on KPMs and tryptophan levels in runners after an ultramarathon. In the study, 35 amateur runners were assigned into two groups: vitamin D supplementation group, administered 150,000 IU vitamin D in vegetable oil 24 h before the run (n = 16); and control (placebo) group (n = 19). Blood was collected for analysis 24 h before, immediately after, and 24 h after the run. Kynurenic, xanthurenic, quinolinic, and picolinic acids levels were significantly increased after the run in the control group, but the effect was blunted by vitamin D supplementation. Conversely, the decrease in serum tryptophan, tyrosine, and phenylalanine levels immediately after the run was more pronounced in the supplemented group than in the control. The 3-hydroxy-l-kynurenine levels were significantly increased in both groups after the run. We conclude that vitamin D supplementation affects ultramarathon-induced changes in tryptophan metabolism.

The Jumper's Knee - a New Look at Non-surgical Treatment. Pilot Study.

BACKGROUND: There are many opinions and views regarding the methods of treatment of patellar ligament enthesopathy. No gold standard of treatment exists. This paper presents our approach involving conservative treatment and an appropriate rehabilitation regime. Our aim was to assess the effectiveness of a combination of various conservative treatment techniques and the time needed to return to sport. MATERIAL AND METHODS: The study enrolled 14 patients treated in 2019 and 2020. Knee joint evaluation was based on clinical and radiological examination (sonography and MR). All patients were treated conservatively according to a specially prepared treatment protocol. Patients were evaluated at two-week intervals until the symptoms subsided completely. The KOOS, Kujala and SF36 questionnaires were used to evaluate the results. RESULTS: All of the patients returned to painless physical activity within 3-4 weeks from the start of treatment. In the group of professional athletes, 100% returned to sport. The return to sport took slightly longer for pa-tients with bilateral (5-6 weeks) in comparison to unilateral jumper's knee (3-4 weeks). The longest period of return to sport, in a patient who had severe pain at rest before starting treatment, was 7 weeks. Statistically significant improvement was noted in all of the questionnaires used and in all subdomains at 6 months after the beginning of the treatment. CONCLUSIONS: 1. The conservative approach proposed by us generated promising results in the treatment of the jumper's knee. 2. A 100% rate of return to sport was recorded among our patients.