1. Introduction
degeneration of substantia nigra pars compacta [, tremor, sleep disturbances, inflammation, dementia, rigidity, Parkinson’s disease, PD, neurotoxic, depression
DISEASE PROGRESSION, MINERALIZATION, NEURODEGENERATIVE DISORDERS, DISEASE, INFLAMMATION
The current study aimed to investigate whether a 12-week Body Mass Index (BMI)-based (the higher the BMI, the higher the dosage) vitamin DThe population of people ages 65 and above is widely associated with neurodegenerative disorders, the second most widespread being Parkinson’s disease (PD). According to World Health Organization, the number of patients suffering from this disease was over 8.5 million in 2019. It is marked by motor symptoms including resting tremor, bradykinesia, and rigidity as well as non-motor symptoms, such as dementia, depression, sleep disturbances, among others. During disease progression, dopamine production drops due to the degeneration of substantia nigra pars compacta [Vitamin D is often described as one of the most relevant vitamins in the human body. It plays multiple roles, e.g., maintaining the calcium and phosphate balance, helping the immune system to differentiate, and increasing bone mineralization [Supplementation of vitamin DResearch on the supplementation of vitamin DThe main route of tryptophan metabolism is the kynurenine pathway (KP). It is activated by indoleamine 2,3-dioxygenase (IDO) and tryptophan 2,3-dioxygenase (TDO). Tryptophan is converted to N-formyl-kynurenine and then quickly to kynurenine (KYN) due to N-formyl-kynurenine’s instability. Subsequently, KYN may be catabolized to 3-hydroksykynurenine (3-HK), kynurenic acid (KYNA), and anthranilic acid (AA). KYNA has neuroprotective properties. 3-HK, which is neurotoxic, is transformed into 3-hydroxyantrhranilic acid (3-HANA) and then catabolized to quinolinic acid (QUIN) or picolinic acid (PA), the first of which is neurotoxic, and the second may be neuroprotective. 3-HK may also be converted to xanthurenic acid (XANA) which also has neurotoxic properties. The kynurenine pathway is often disturbed in PD [In PD patients, the markers of inflammation are often elevated compared with the healthy age-matched controls [In our previous study [