Vitamin D and cognitive functions: What do research say
Content
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Introduction to vitamin D: essence, sources and metabolism
1.1. What is vitamin D? Classification and forms
1.2. The main sources of vitamin D: sun, food and additives
1.3. Vitamin D metabolism: from skin to active hormone
1.4. Recommended vitamin D consumption standards: international standards and individual needs
1.5. Factors affecting the level of vitamin D: geography, age, skin pigmentation and lifestyle
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Cognitive functions: definition, main areas and assessment methods
2.1. What are cognitive functions? Overview of key areas
2.2. Attention: types, processes and methods of evaluation
2.3. Memory: classification, mechanisms and neurobiological foundations
2.4. Language: components, processing and disorder
2.5. Executive functions: planning, flexibility of thinking and impulse control
2.6. Methods for evaluating cognitive functions: neuropsychological testing and neuroizualization
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Vitamin D and brain: neurobiological mechanisms
3.1. Vitamin D (VDR) receptors in the brain: localization and functions
3.2. Vitamin D and neurotransmitters: the effect on synthesis and metabolism
3.3. Vitamin D and neuroprotection: antioxidant and anti -inflammatory properties
3.4. Vitamin D and neurogenesis: the role in the development and restoration of nervous tissue
3.5. Vitamin D and modulation of genes expression in the brain: Epigenetic mechanisms
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Research review: the effect of vitamin D on cognitive functions in various age groups
4.1. Vitamin D and cognitive development in children and adolescents
4.1.1. The influence of vitamin D levels during pregnancy on the cognitive development of the child
4.1.2. The influence of vitamin D on academic performance and academic achievements of schoolchildren
4.1.3. Vitamin D and autistic spectrum disorders (RAS): communication and potential mechanisms
4.1.4. Vitamin D and attention deficiency syndrome (hyperactivity): research data
4.2. Vitamin D and cognitive functions in adults
4.2.1. Vitamin D and improving memory and attention in young and middle -aged adults
4.2.2. Vitamin D and prevention of cognitive disorders in old age
4.2.3. Vitamin D and the risk of developing Alzheimer’s disease and other dementia
4.2.4. Vitamin D and vascular dementia: interconnection and mechanisms
4.2.5. The effect of vitamin D on cognitive functions in patients with multiple sclerosis
4.2.6. Vitamin D and cognitive disorders for depression and other mental disorders
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Vitamin D and cognitive functions in various diseases and conditions
5.1. Vitamin D and cognitive functions with cardiovascular diseases
5.1.1. Vitamin D, arterial hypertension and cognitive disorders
5.1.2. Vitamin D and cognitive functions after stroke
5.2. Vitamin D and cognitive functions with metabolic syndrome and diabetes
5.2.1. Vitamin D, insulin resistance and cognitive deficit
5.2.2. Vitamin D and diabetic encephalopathy
5.3. Vitamin D and cognitive functions in autoimmune diseases
5.3.1. Vitamin D and cognitive disorders with a systemic lupus erythematosus
5.3.2. Vitamin D and cognitive functions with rheumatoid arthritis
5.4. Vitamin D and cognitive functions for infectious diseases
5.4.1. Vitamin D and neurocognitive consequences Covid-19
5.4.2. Vitamin D and cognitive disorders for HIV infection
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Vitamin D influence mechanisms on cognitive functions: in -depth analysis
6.1. Vitamin D and inflammation: influence on cytokines and microlytes
6.2. Vitamin D and oxidative stress: antioxidant mechanisms
6.3. Vitamin D and neurotrophic factors: BDNF and NGF
6.4. Vitamin D and regulation of calcium levels in neurons: influence on synaptic transmission
6.5. Vitamin D and angiogenesis in the brain: role in maintaining cerebral blood flow
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Clinical research and meta analysis: evidence of the effectiveness of vitamin D to improve cognitive functions
7.1. Analysis of randomized controlled studies (RCTs): design, participants and results
7.2. Meta analysis: combining these several studies to evaluate the overall effect
7.3. Assessment of research quality: Criteria and methodology
7.4. Factors affecting research results: vitamin D dosage, duration of admission and characteristics of participants
7.5. Systematic reviews: a critical assessment of existing evidence
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Optimal strategies for using vitamin D to maintain and improve cognitive functions
8.1. Determining the level of vitamin D in the blood: methods and interpretation of the results
8.2. Vitamin D dosage: Recommendations and individual approach
8.3. Forms of vitamin D: D2 (ergocalciferol) and d3 (cholecalciferol)
8.4. Ways to use vitamin D: oral additives, intramuscular injections and ultraviolet irradiation
8.5. Vitamin D Monitoring and dose adjustment
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Vitamin D: side effects and contraindications safety safety
9.1. Hypervitaminosis D: causes, symptoms and treatment
9.2. Side effects of taking vitamin D: gastrointestinal disorders, hypercalcemia and renal failure
9.3. Contraindications to the use of vitamin D: some kidney diseases, hypercalcemia and hyperparathyroidism
9.4. Interaction of vitamin D with other drugs
9.5. Special groups of patients: pregnant and nursing women, children and elderly people
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Future research areas: prospects and unresolved issues
10.1. The need to conduct large -scale randomized controlled research
10.2. The study of genetic factors affecting the effectiveness of vitamin D
10.3. The study of the effect of vitamin D on the intestinal microbia and its connection with cognitive functions
10.4. Development of new forms of vitamin D with improved bioavailability
10.5. The study of vitamin D interaction mechanisms with other nutrients and their synergistic effect on cognitive functions
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Conclusion: the role of vitamin D in maintaining cognitive health and prospects for further research.
1. Introduction to vitamin D: essence, sources and metabolism
1.1. What is vitamin D? Classification and forms
Vitamin D, often called “solar vitamin”, is a group of fat -soluble runners necessary for many physiological processes in the body. Although it is called vitamin, it functions rather like a hormone, associated with vitamin D receptors in various tissues, including the brain, and affecting the expression of genes. The main forms of vitamin D include:
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Vitamin D2 (ergocalciferol): It is produced by plants and mushrooms under the influence of ultraviolet (UV) radiation. It is often used as a food supplement, especially in enriched food.
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Vitamin D3 (cholecalciferol): It is synthesized in the skin of humans and animals under the influence of UV radiation. Also contained in some products of animal origin. It is believed that vitamin D3 is more effective in increasing the level of vitamin D in the blood compared to vitamin D2.
Both forms of vitamin D are inactive and need a two-stage hydroxylation process in the liver and kidneys to turn into an active form, calcitriol (1,25-dihydroxyvitamin D3).
1.2. The main sources of vitamin D: sun, food and additives
Obtaining a sufficient amount of vitamin D may be a difficult task, especially in the winter months or for people living in the northern latitudes. The main sources of vitamin D include:
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Sunlight: The most natural and effective way to produce vitamin D. Ultraviolet rays B (UV-B) penetrate the skin and stimulate the synthesis of vitamin D3. The duration of the sun, necessary for the synthesis of a sufficient amount of vitamin D, depends on many factors, including the season, time of day, breadth, pigmentation of the skin and the use of sunscreen. People with dark skin require more time being in the sun to synthesize the same amount of vitamin D as people with light skin. Using a high SPF sunscreen can significantly reduce the synthesis of vitamin D.
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Food: Vitamin D is contained in a small number of food, such as:
- Fat fish (salmon, tuna, mackerel)
- Egg yolks (contain vitamin D only from chickens that have received enough vitamin D)
- Beef liver
- Enriched food (milk, orange juice, cereals)
The amount of vitamin D in these products can vary depending on the diet of animals and the process of enrichment.
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Supplements: Vitamin D3 and D2 are available in the form of food additives in various dosages. Vitamin D additives are an effective way to increase vitamin D levels in the blood, especially for people who do not get enough sunlight or have dietary restrictions. It is important to consult a doctor to determine a suitable dosage.
1.3. Vitamin D metabolism: from skin to active hormone
Vitamin D metabolism is a complex process that includes several stages:
- Synthesis in leather or absorption from screams: Vitamin D3 is synthesized in the skin under the influence of UV radiation or absorbed from food in the form of D2 or D3.
- The first hydroxylation in the liver: Vitamin D (D2 or D3) is transported to the liver, where, under the influence of an enzyme 25-hydroxylasis, it turns into 25-hydroxyvitamin D [25(OH)D]also known as calciol. 25 (OH) D is the main form of vitamin D, circulating in the blood, and is used to assess the status of vitamin D.
- The second hydroxylation in the kidneys: 25 (OH) D is transported to the kidneys, where, under the influence of an enzyme 1-alpha-hydroxylase, it turns into 1.25-dihydroxyvitamin D [1,25(OH)2D]also known as calcitriol. Calcitriol is an active form of vitamin D and is associated with VDR in various tissues, including the brain, having its biological effects.
- Regulation: Transformation 25 (OH) D into calcitriol is rigidly regulated by parathormone (PTH), calcium and phosphorus. When the level of calcium in the blood falls, PTG stimulates the formation of calcitriol, which increases the absorption of calcium in the intestines, reabsorption of calcium in the kidneys and the release of calcium from bones.
1.4. Recommended vitamin D consumption standards: international standards and individual needs
Recommended vitamin D consumption standards vary depending on age, health and international standards. Some organizations, such as the Institute of Medicine (IOM) in the USA, establish recommended dietary standards (RDA) and the upper permissible levels of consumption (UL).
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Recommended dietary norm (RDA):
- Infants (0-12 months): 400 IU (10 μg)
- Children and adults (1-70 years old): 600 IU (15 mcg)
- Adults (older than 70 years): 800 IU (20 μg)
- Pregnant and lactating women: 600 IU (15 μg)
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The upper permissible level of consumption (UL):
- Infants (0-12 months): 1000 IU (25 μg)
- Children (1-8 years old): 4000 IU (100 mcg)
- Children (9 years and older) and adults: 4000 IU (100 mcg)
It is important to note that these recommendations are common and individual needs may differ. Some experts believe that to maintain the optimal level of vitamin D in the blood, a higher dosage may be required, especially for people with a deficiency of vitamin D or with risk factors. The optimal level of vitamin D in the blood (25 (OH) D) is usually considered higher than 30 ng/ml (75 nmol/l). To determine the individual needs of vitamin D, it is recommended to consult a doctor.
1.5. Factors affecting the level of vitamin D: geography, age, skin pigmentation and lifestyle
Many factors can affect the level of vitamin D in the body:
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Geography: People living in the northern latitudes, where there are fewer sunlight, especially in the winter months, are at greater risk of vitamin D deficiency. The angle of fall of sunlight and cloudiness can also affect the amount of UV radiation reaching the skin.
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Age: With age, the ability of the skin to synthesize vitamin D decreases. In addition, older people often spend less time in the open air and may have problems with the absorption of vitamin D from food.
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Pigmentation leather: Melanin, the pigment responsible for skin color, absorbs UV-B radiation, reducing the synthesis of vitamin D. People with dark skin need more time in the sun to synthesize the same amount of vitamin D as people with light skin.
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Life:
- Diet: Insufficient consumption of products rich in vitamin D can contribute to vitamin D.
- Sun stay: Insufficient stay in the sun or the use of sunscreen can reduce the synthesis of vitamin D.
- Obesity: Vitamin D is fat -soluble and can accumulate in adipose tissue, reducing its availability for blood circulation. Obesity people often have a lower level of vitamin D in the blood.
- Some diseases: Some diseases, such as Crohn’s disease, celiac disease and cystic fibrosis, may disrupt the absorption of vitamin D from the intestines.
- Some drugs: Some drugs, such as glucocorticoids, antifungal drugs and anticonvulsants, can affect vitamin D.’s metabolism.
2. Cognitive functions: definition, main areas and assessment methods
2.1. What are cognitive functions? Overview of key areas
Cognitive functions relate to mental processes that allow us to perceive, study, memorize, reason, solve problems and interact with the outside world. They cover a wide range of abilities, including attention, memory, language, executive functions and visual-spatial skills. Cognitive functions are necessary for everyday life and affect our ability to work, study, communicate and make decisions.
Key areas of cognitive functions:
- Attention: The ability to concentrate on certain information, ignoring distracting factors.
- Memory: The ability to encode, store and extract information.
- Language: The ability to understand and use oral and written speech.
- Executive functions: A set of cognitive processes that allow us to plan, organize, regulate behavior and solve problems.
- Visual-spatial skills: The ability to perceive and manipulate objects in space.
2.2. Attention: types, processes and methods of evaluation
Attention is a complex cognitive process that allows us to selectively focus on certain incentives or tasks, ignoring distracting factors. There are different types of attention:
- Sustainable attention: The ability to maintain concentration for a long period of time.
- Selective attention: The ability to focus on a certain stimulus, ignoring other stimuli.
- Separated attention: The ability to simultaneously concentrate on several tasks.
- Switching attention: The ability to switch between different tasks or stimuli.
Attention processes include:
- Vigilance: A state of increased readiness to detect targeted stimuli.
- Orientation: The direction of attention to a certain incentive.
- Executive Department: Control and regulation of attention.
Attention assessment methods:
- Continuous performance test (CPT): Measures stable attention and impulsiveness.
- Test gate: Evals selective attention and control of impulses.
- Tracking test: Assesses visual attention and speed of information processing.
- Tests for divided attention: Assess the ability to simultaneously perform several tasks.
2.3. Memory: classification, mechanisms and neurobiological foundations
Memory is the ability to encode, store and extract information. There are different types of memory:
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Sensory memory: Short -term storage of sensory information (for example, visual or auditory).
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Short -term memory: Temporary storage of information used for current tasks.
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Working memory: A system that allows you to hold and manipulate information in short -term memory.
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Long -term memory: Constant storage of information.
- Explicit (declarative) memory: Memory of facts and events.
- Episodic memory: Memory of personal events and experiences.
- Semantic memory: Memory of facts and knowledge.
- Implicit (procedural) memory: Memory of skills and habits.
- Explicit (declarative) memory: Memory of facts and events.
Memory mechanisms:
- Coding: The process of converting information into a form suitable for storage in memory.
- Storage: Maintaining information in memory over time.
- Extraction: Obtaining access to information stored in memory.
Neurobiological foundations of memory:
- Hippocampus: Plays an important role in the formation of new long -term memories.
- Almond -shaped body: Participates in the processing of emotional memories.
- Prefrontal bark: Participates in working memory and enforcement control.
2.4. Language: components, processing and disorder
Language is a complex system of characters and rules used for communication. It consists of several components:
- Phonetics: Studying the sounds of speech.
- Phonology: Learning a system of sounds in the language.
- Morphology: Studying the structure of words.
- Syntax: Studying the rules for building proposals.
- Semantics: Studying the meaning of words and sentences.
- Pragmatics: Learning the use of language in context.
Language processing includes:
- Understanding speech: Perception and interpretation of oral speech.
- Speech production: Formation and articulation of oral speech.
- Reading: Perception and understanding of written speech.
- Letter: Formation and recording of written speech.
Speech and language disorders:
- Aphasia: Speech disorders caused by brain damage.
- Dyslexia: Violation of reading.
- Dysgraphia: Violation of the letter.
- Stuttering: Violation of the smoothness of speech.
2.5. Executive functions: planning, flexibility of thinking and impulse control
Executive functions are a set of cognitive processes that allow us to plan, organize, regulate behavior and solve problems. They include:
- Planning: The ability to develop and organize steps to achieve the goal.
- Working memory: The ability to hold and manipulate information in the mind.
- Flexibility of thinking: The ability to switch between different tasks or strategies.
- Impulse control: The ability to suppress impulsive reactions.
- Decision -making: The ability to evaluate options and choose the optimal solution.
- Problem solution: The ability to find solutions to complex problems.
- Abstract thinking: The ability to understand abstract concepts and relationships.
2.6. Methods for evaluating cognitive functions: neuropsychological testing and neuroizualization
Assessment of cognitive functions can be carried out using various methods, including neuropsychological testing and neuroimaging.
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Neuropsychological testing: Uses standardized tests to evaluate various cognitive functions, such as attention, memory, language, executive functions and visual-spatial skills. The test results are compared with regulatory data to determine the presence of cognitive deficiency. Examples of neuropsychological tests include:
- Mini-Mental State Examination (MMSE): General screening test for evaluating cognitive functions.
- Montreal Cognitive Assessment (MoCA): A more sensitive screening test for identifying light cognitive impairment.
- Wechsler Adult Intelligence Scale (WAIS): Test for assessing intelligence and cognitive abilities.
- Rey Auditory Verbal Learning Test (RAVLT): Test for evaluating verbal memory.
- Wisconsin Card Sorting Test (WCST): Test for evaluating executive functions, including flexibility of thinking and planning.
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Neurovalization: Uses the methods of visualization of the brain to assess the structure and function of the brain. Examples of neuroimaging methods include:
- Magnetic resonance tomography (MRI): Uses magnetic fields and radio waves to obtain detailed images of the structure of the brain.
- Computed tomography (CT): Uses x -rays to obtain images of the structure of the brain.
- Positron emission tomography (PET): Uses radioactive substances to assess the metabolic activity of the brain.
- ElectroenceianChalograph (GCH): It measures the electrical activity of the brain using electrodes placed on the scalp.
- Functional magnetic resonance imaging (FMRT): It measures the activity of the brain by detecting changes in the bloodstream.
3. Vitamin D and brain: neurobiological mechanisms
3.1. Vitamin D (VDR) receptors in the brain: localization and functions
Vitamin D (VDR) receptors are widely represented in various areas of the brain, which indicates an important role of vitamin D in neurobiological processes. VDR are found in the following areas of the brain:
- Hippocampus: Plays an important role in the formation of new memories and spatial orientation.
- Prefrontal bark: Participates in executive functions, planning, decision -making and working memory.
- Cerebellum: Participates in coordination of movements, balance and motor education.
- Hypothalamus: Participates in the regulation of appetite, sleep, body temperature and hormonal balance.
- Black substance: Participates in the production of dopamine, neurotransmitter, important for movement, motivation and remuneration.
- GIPLE: Astrocytes and microlytes that play an important role in support and protection of neurons.
VDR functions in the brain:
- Gene expression regulation: VDR is associated with DNA and regulates the expression of genes involved in various neurobiological processes, such as neurogenesis, synaptogenesis, neuroprotement and inflammation.
- Modulation of neurotransmissions: VDR affects the synthesis, release and metabolism of neurotransmitters, such as dopamine, serotonin and acetylcholine.
- Protection from neurodegeneration: VDR has a neuroprotective effect, protecting neurons from oxidative stress, inflammation and ex -tootoxicity.
- Calcium regulation: VDR is involved in the regulation of the level of calcium in neurons, which is important for synaptic transmission and neuronal excitability.
- Neuroplastic support: VDR plays a role in neuroplasticity, the ability of the brain to change its structure and function in response to experience.
3.2. Vitamin D and neurotransmitters: the effect on synthesis and metabolism
Vitamin D affects the synthesis and metabolism of various neurotransmitters that play an important role in cognitive functions:
- Dofamine: Vitamin D stimulates the synthesis of dopamine in black substance and other areas of the brain. Dopamine is important for motivation, reward, training and movement. Dopamine deficiency is associated with Parkinson’s disease, depression and attention disorders.
- Serotonin: Vitamin D is involved in the synthesis of serotonin, neurotransmitter that regulates mood, sleep, appetite and social behavior. Serotonin deficiency is associated with depression, anxiety and sleep disturbances.
- Acetylcholine: Vitamin D can affect the synthesis and release of acetylcholine, neurotransmitter, important for memory, learning and attention. Acetylcholine deficiency is associated with Alzheimer’s disease.
- Gamk (gamma-aminobral acid): Vitamin D can modulate the activity of the GABA, the main brake neurotransmitter in the brain. GABA plays an important role in the regulation of neuronal excitability and a decrease in anxiety.
The influence of vitamin D on neurotransmitters can explain its connection with cognitive functions and mental health.
3.3. Vitamin D and neuroprotection: antioxidant and anti -inflammatory properties
Vitamin D has neuroprotective properties, protecting neurons from damage caused by oxidative stress, inflammation and other factors.
- Antioxidant properties: Vitamin D is an antioxidant and helps to protect neurons from damage caused by free radicals. Oxidative stress plays an important role in the development of neurodegenerative diseases, such as Alzheimer’s disease and Parkinson’s disease.
- Anti -inflammatory properties: Vitamin D has anti -inflammatory properties and can reduce the level of inflammatory cytokines in the brain. Chronic inflammation is associated with an increased risk of cognitive disorders and neurodegeneration. Vitamin D can modulate the activity of microglia, immune brain cells to reduce inflammation.
- Protection against exteitotoxicity: Vitamin D can protect neurons from exteitotoxicity, damage caused by excessive stimulation of neurons by glutamate. Ex -tootoxicity can play a role in the development of neurodegenerative diseases and stroke.
3.4. Vitamin D and neurogenesis: the role in the development and restoration of nervous tissue
Neurogenesis is the process of the formation of new neurons in the brain. An adult neurogenesis occurs in certain areas of the brain, such as hippocampus and olfactory bulb, and plays an important role in teaching, memory and mood.
Vitamin D plays a role in neurogenesis:
- Stimulation of the proliferation of neuronal predecessor cells: Vitamin D stimulates the proliferation and differentiation of neuronal predecessor cells, increasing the number of new neurons.
- Improving the survival of neurons: Vitamin D improves the survival of new neurons, protecting them from damage and apoptosis (programmable cell death).
- Regulation of the expression of genes participating in neurogenesis: Vitamin D regulates the expression of genes involved in neurogenesis, such as BDNF (neurotrophic factor of the brain).
The effect of vitamin D on neurogenesis can help improve cognitive functions and restore after brain damage.
3.5. Vitamin D and modulation of genes expression in the brain: Epigenetic mechanisms
Vitamin D is associated with VDR, which, in turn, is associated with DNA and regulates the expression of genes. This process may include epigenetic mechanisms, such as DNA methylation and histone modification.
- DNA methylation: Vitamin D can affect DNA methylation, a process that can change the activity of genes. DNA methylation may be associated with the development of neurodegenerative diseases and cognitive disorders.
- Modifications of histones: Vitamin D can affect the modifications of histones, proteins around which DNA is wrapped. Histonian modifications can affect the availability of DNA for transcription and, therefore, on the expression of genes.
Modulation of genes expression under the influence of vitamin D can play an important role in its effect on cognitive functions and neurodegenerative diseases.
4. Review review: the effect of vitamin D on cognitive functions in different age groups
4.1. Vitamin D and cognitive development in children and adolescents
4.1.1. The influence of vitamin D levels during pregnancy on the cognitive development of the child
Several studies studied the effect of vitamin D levels during pregnancy on the cognitive development of the child. Some studies have shown that vitamin D deficiency during pregnancy can be associated with an increased risk of cognitive disorders, delayed speech development and behavioral disorders in children. Other studies have not revealed a significant connection.
Possible mechanisms of vitamin D during pregnancy on the cognitive development of the child include:
- The role of vitamin D in the development of the brain of the fetus: Vitamin D plays an important role in the development of the brain of the fetus, affecting neurogenesis, synaptogenesis and myelinization.
- Regulation of the expression of genes involved in the development of the brain: Vitamin D regulates the expression of genes involved in the development of the brain through VDR.
- Influence on the immune system of the mother and fetus: Vitamin D affects the immune system of the mother and fetus, which can affect the development of the brain.
Further research is needed to confirm these results and determine the optimal level of vitamin D during pregnancy to support the cognitive development of the child.
4.1.2. The influence of vitamin D on academic performance and academic achievements of schoolchildren
Not