I was always very curious about vitamin d,…and why it helps us soo much.
and here´s what I found
Hypovitaminosis D[edit]
Hypovitaminosis D is described as any deficiency of vitamin D. A vitamin D blood concentration standard for diagnosing hypovitaminosis D does not exist. In the past, hypovitaminosis D has been defined by blood concentrations lower than 20 ng/ mL.[5] However, in more recent literature many researchers have considered 30 ng/ mL to be an insufficient concentration of vitamin D.[5] Subnormal levels of vitamin D are usually caused by poor nutrition or a lack of sun exposure.[4] Risk factors for hypovitaminosis D include premature birth, darker skin pigmentation, living at higher altitudes, obesity, malabsoprtion and older age.
Vitamin D and the central nervous system[edit]
Location in the central nervous system[edit]
The brain requires the use of many neurosteroids to develop and function properly. These molecules are often identified as one of many common substances including thyroid hormones, glucocorticoids, and androgens. However in recent studies, throughout the brain and spinal fluid, vitamin D has begun to surface as one of these neurosteroids.
Metabolites: Several vitamin D metabolites are found in cerebral spinal fluid and have the ability to cross the blood brain barrier. This is similar to many of the previously known neurosteroids. These vitamin D metabolites include 25-hydroxyvitamin D3, 1,25-dihydroxyvitamin D3, and 24,25-dihydroxyvitamin D3.[1] Derivatives of these metabolites are highly expressed in the substantia nigra and the hypothalamus. These two brain structures are responsible for motor functions and linking the nervous system to the endocrine system, respectively. The expression of these metabolite derivatives in these areas suggests that these structures have the ability to synthesize these products from vitamin D.[1]
Location of brain regions related to vitamin D.
Receptors: In addition to vitamin D metabolites, vitamin D receptor (VDR) proteins are also found in the brain; more specifically, they are found in the cerebellum, thalamus, hypothalamus, basal ganglia, and hippocampus.[1] The highest density of VDR is in substantia nigra, one of the primary areas of dopamine production. Another significant portion of the receptors is located in the hypothalamus (supra optic and paraventricular nuclei) and external granule cell layer of the prefrontal cortex.[6] VDR are also found in the hippocampus (CA1 and CA2) areas, in slightly lower densities.
Function in the central nervous system[edit]
The presence of vitamin D, it’s activating enzyme, and VDR in the brain leads researchers to question what role vitamin D plays in the brain. Research suggests that vitamin D may functions as a modulator in brain development and as a neuroprotectant.[1] In recent studies, vitamin D has exhibited an association with the regulation of nerve growth factor (NGF) synthesis. NGF is responsible for the growth and survival of neurons.[7] This relationship has also been studied in embryonic and neonatal rats. Developmental vitamin D deficient (DVD) rats have decreased levels of neurotrophic factors, increased mitosis, and decreased apoptosis. These findings suggest that vitamin D potentially affects the development of neurons as well as their maintenance and survival. Current research is underway investigating whether vitamin D is a factor contributing to normal brain functioning.
Vitamin D and neurological disorders[edit]
Hypovitaminosis D is associated with several neuropsychiatric disorders including dementia, Parkinson’s disease, multiple sclerosis, epilepsy, and schizophrenia. There are several proposed mechanisms by which hypovitaminosis D may impact these disorders. One of these mechanisms is through neuronal apoptosis. Neuronal apoptosis is the programmed death of the neurons. Hypovitaminosis D causes this specific apoptosis by decreasing the expression of cytochrome C and decreasing the cell cycle of neurons. Cytochrome C is a protein that promotes the activation of pro-apoptotic factors.[8] A second mechanism is through the association of neurotrophic factors like nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), glial cell line-derived neurotrophic factor (GDNF). These neurotrophic factors are proteins that are involved in the growth and survival of developing neurons and they are involved in the maintenance of mature neurons.[9]
Dementia: Alzheimer’s disease[edit]
Notice the shrunken and enlarged portions of the brain
The image compares the brain of a normal adult to that of a patient with Alzheimer’s disease
“Dementia” is a term referring to neurodegenerative disorders characterized by a loss of memory and such brain functions executive functioning. Included under this umbrella term is Alzheimer’s disease. Alzheimer’s disease is characterized by the loss of cortical functions like language and motor skills.[6] Patients with Alzheimer’s disease exhibit an extreme shrinkage of the cerebral cortex and hippocampus with an enlargement of the ventricles. In several recent studies, higher vitamin D levels have been associated with lower risks of developing Alzheimer’s disease.[10] Alzheimer’s disease is associated with a decrease in vitamin D receptors in the Cornu Ammonius areas (CA 1& 2) of the hippocampus.[6] The hippocampus is a portion of the limbic system responsible for memory and spatial navigation. Additionally, VDR haplotypes were associated detected with increased frequency in patient with Alzheimer’s disease while other VDR haplotypes were detected with increased frequency, suggesting that specific haplotypes may increase or decrease risk of developing Alzheimer’s.[11][12] It is hypothesized that this lack of VDRs in the hippocampus prevents the proper functioning (ie. memory) of this structure.
Parkinson’s disease[edit]
This image depicts the circuits of the basal ganglia in patients with Parkinson’s disease. Pay close attention to the role of the substantia nigra and the dopaminergic neurons
Parkinson’s disease is characterized by progressive deterioration of movement and coordination. Patients with Parkinson’s disease lose dopaminergic (DA) neurons in the substantia nigra.,[13] a part of the brain that plays a central role in such brain functions as reward, addiction, and coordination of movement. Studies suggest that low vitamin D levels could play a role in PD, and in one case report, vitamin D supplements lessened parkinsonian symptoms. In a study of vitamin D receptor knockout mice, mice without VDR exhibited motor impairments similar to impairments seen in patients with Parkinson’s disease.[6] One proposed mechanism linking vitamin D to Parkinson’s disease involves the Nurr 1 gene. Vitamin D deficiency is associated with decreased expression of the Nurr1 gene, a gene responsible for development of DA neurons. It is therefore plausible that a lack of Nurr1 expression leads to impaired DA neuronal development. Failure to form DA neurons would lead to lower dopamine concentrations in the basal ganglia. Additionally, rats lacking Nurr1 exhibited hypoactivity followed by death shortly after birth.[13]
Multiple sclerosis[edit]
Multiple sclerosis (MS) is an autoimmune disease causing demyelination within the central nervous system.[14] In the central nervous system, there are many cells encased in a fatty coating called the myelin sheath. This sheath allows for informational signals to be transmitted at greater speeds down through the cell. In multiple sclerosis, this sheath deterioration causes a slower transmission of nerve signals. This ultimately results in severe motor deficits.
The prevalence of MS is associated with latitude. In this image, red indicates a high prevalence of MS while yellow indicates a lower prevalence
There is a well-established global correlation between multiple sclerosis and latitude; there is a higher multiple sclerosis prevalence in northeastern regions than in the south and western regions. At the same time, on average higher vitamin D levels are found in the south and western regions than in the northeast.[14] Based on this correlation and other studies, the higher intake of vitamin D is associated with a lower risk for MS.[14] The mechanism for this association is not fully established, however, a proposed mechanism involves inflammatory cytokines. Hypovitaminosis D is associated with an increase in pro-inflammatory cytokines and decrease in anti-inflammatory cytokines. The increase in these specific cytokines is associated with the degradation of the myelin sheath.[15]
FOCUS on this
Metabolites: Several vitamin D metabolites are found in cerebral spinal fluid and have the ability to cross the blood brain barrier. This is similar to many of the previously known neurosteroids.
I couldnt help but to link this with cerebrolysin, seriously guys you need to look into this, Its like re wiring everything back in place!!