Vitamin D: Why is it needed and how to get it?

Vitamin D: Why is it needed and how to get it?

I. The role of vitamin D in human health

Vitamin D, despite the name “vitamin”, is inherently a run of a critical role in maintaining calcium and phosphate homeostasis, as well as in the regulation of many other physiological processes in the body. Its influence extends from strengthening bones and teeth to support for the immune system and protection against chronic diseases.

A. Metabolism and forms of vitamin D:

Vitamin D exists in two main forms: vitamin D2 (ergocalciferol) and vitamin D3 (cholegalciferol). Vitamin D2 is contained in some plants and fungi, and vitamin D3 is synthesized in the skin under the influence of ultraviolet B (UVB) radiation of sunlight, and is also present in certain products of animal origin.

• Vitamin D3 synthesis in the skin: When the UVB radiation enters the skin, it converts a 7-dehydrocholesterin (predecessor of cholesterol) into previtamin D3. Previtamin D3 is then is metered in vitamin D3. This process depends on many factors, including the time of day, season, breadth of terrain, cloudiness, skin color and the use of sunscreen.

• Transformation in the liver and kidneys: Both vitamin D2 and vitamin D3 are inactive in their original form. They must pass two stages of hydroxylation to become biologically active. The first stage occurs in the liver, where vitamin D turns into 25-hydroxyvitamin D [25(OH)D]also known as calciol. Calcidia is the main form of vitamin D, circulating in the blood, and is used to assess the level of vitamin D in the body. The second stage of hydroxylation occurs in the kidneys, where calciol turns into 1.25-dihydroxyvitamin D [1,25(OH)2D]also known as calcitriol. Calcitriol is a biologically active form of vitamin D and has its effect, associated with vitamin D (VDR) receptors in various body tissues.

B. The main functions of vitamin D:

• Regulation of the metabolism of calcium and phosphates: Vitamin D plays a key role in maintaining the normal level of calcium and phosphates in the blood necessary for the health of bones, teeth and normal functioning of the nervous system and muscles. It contributes to the absorption of calcium in the intestines, calcium reabsorption in the kidneys and mobilization of calcium from bones when the level of calcium in the blood falls.

• Bone health and prevention of osteoporosis: Vitamin D is necessary for the mineralization of bones, a process in which calcium and phosphates are deposited in bone tissue, making it strong and dense. Vitamin D deficiency can lead to rickets in children and osteomination in adults, diseases characterized by weak and soft bones. Vitamin D also plays an important role in the prevention of osteoporosis, a disease characterized by a decrease in bone density and an increased risk of fractures.

• Support for the immune system: Vitamin D plays an important role in the modulation of the immune system. It helps to activate immune cells, such as T cells and B cells that are necessary to combat infections. Vitamin D can also help reduce the risk of autoimmune diseases such as multiple sclerosis, type 1 diabetes and rheumatoid arthritis.

• Regulation of cellular growth and differentiation: Vitamin D is involved in the regulation of cellular growth, differentiation and apoptosis (programmable cell death). Studies show that vitamin D can play a role in the prevention of some types of cancer, including colon cancer, breast cancer and prostate cancer.

• Master maintenance of muscle function: Vitamin D is necessary to maintain a normal muscle function. Vitamin D deficiency can lead to muscle weakness, muscle pain and increased risk of falls, especially in the elderly.

• Influence on the cardiovascular system: Studies show that vitamin D deficiency can be associated with an increased risk of cardiovascular disease, such as hypertension, coronary heart disease and stroke. Vitamin D can have a protective effect on the cardiovascular system, reducing inflammation, regulating blood pressure and improving the function of the endothelium.

• Regulation of mood and cognitive functions: Some studies associate the deficiency of vitamin D with an increased risk of depression, seasonal affective disorder (SAR) and cognitive disorders. Vitamin D can affect the mood and cognitive functions, acting on neurotransmitters, such as serotonin and dopamine.

II. Vitamin D: causes, symptoms and diagnosis

Vitamin D deficiency is a common problem around the world, especially among people living in northern latitudes, people with dark skin, elderly people and people with certain diseases.

A. The causes of vitamin D deficiency:

• Insufficient exposure to sunlight: The main cause of vitamin D deficiency is the insufficient effect of the UVB radiation of sunlight. Factors affecting the synthesis of vitamin D in the skin include the season, time of day, breadth of terrain, cloudiness, air pollution, the use of sunscreen, clothing and skin color. People with dark skin need a greater time to stay in the sun to synthesize a sufficient amount of vitamin D.

• Insufficient consumption of vitamin D with food: Some foods contain vitamin D, but their content is usually small. The products rich in vitamin D include oily fish (salmon, tuna, mackerel), egg yolks and enriched products (milk, yogurt, juice).

• Vitamin D of absorption of vitamin D: Some diseases, such as celiac disease, Crohn’s disease and cystic fibrosis, may disrupt the absorption of vitamin D in the intestines.

• Liver and kidney diseases: Diseases of the liver and kidneys can violate the hydroxylation process of vitamin D, necessary for its activation.

• Reception of some drugs: Some drugs, such as anticonvulsants, glucocorticoids and antiretroviral drugs, can reduce vitamin D levels in the blood.

• Obesity: Vitamin D is a fat -soluble vitamin, so in people with obesity more vitamin D is stored in adipose tissue, which makes it less accessible to the body.

B. Symptoms of vitamin D:

Symptoms of vitamin D deficiency can be non -specific and often go unnoticed. The most common symptoms include:

• Fatigue and weakness: Chronic fatigue and weakness can be a sign of vitamin D. deficiency.

• Bone pain and muscles: Vitamin D deficiency can cause pain in bones and muscles, especially in the back, legs and pelvis.

• Muscle weakness: Muscle weakness can lead to difficulties when climbing the stairs, climbing from the chair and performing other everyday tasks.

• Frequent infections: Vitamin D plays an important role in maintaining the immune system, so its deficiency can lead to frequent infections.

• Depression and mood swings: Vitamin D deficiency can be associated with depression, seasonal affective disorder (SAR) and other mood swings.

• Slow wound healing: Vitamin D is necessary for normal wound healing, so its deficiency can slow down this process.

• Hair loss: In some cases, vitamin D deficiency can lead to hair loss.

• In children: In children, vitamin D deficiency can lead to rickets, a disease characterized by bone deformation, growth and development delay.

C. Diagnosis of vitamin D:

The diagnosis of vitamin D deficiency is based on blood tests, which measures the level of 25-hydroxyvitamin D [25(OH)D]. The optimal level 25 (OH) D is from 30 to 50 ng/ml (75-125 nmol/l). The level below 20 ng/ml (50 nmol/l) is considered a deficiency of vitamin D.

III. Ways to obtain vitamin D

There are three main ways to produce vitamin D: exposure to sunlight, consumption of foods rich in vitamin D, and taking vitamin D.

A. The effect of sunlight:

Sunlight is the main source of vitamin D for most people. However, the amount of vitamin D, which can be synthesized in the skin, depends on many factors.

• Top of year and time of day: In the northern latitudes of the UVB-radiation of sunlight is not strong enough in the winter months to stimulate the synthesis of vitamin D in the skin. The best time to get vitamin D from the sun is the middle of the day when the sun is at zenith.

• The latitude of the terrain: People living in the northern latitudes (above 37 degrees of northern latitude) have fewer opportunities for the synthesis of vitamin D from the sun, especially in the winter months.

• Cloud and air pollution: Clouds and air pollution can block UVB radiation and reduce the synthesis of vitamin D in the skin.

• Skin color: People with dark skin need more time being in the sun to synthesize a sufficient amount of vitamin D than people with light skin.

• Use of sunscreen: Sunscreen with SPF 15 and above can block up to 99% UVB radiation and significantly reduce the synthesis of vitamin D in the skin.

• Recommendations: In general, it is recommended to spend 10-15 minutes a day in the sun, several times a week, without sunscreen to ensure sufficient vitamin D. However, it is important to remember the risk of sunburn and observe precautions to protect the skin from the harmful effects of solar radiation.

B. Food products rich in vitamin D:

Some foods contain vitamin D, but their content is usually small.

• Fat fish: Fat fish, such as salmon, tuna, mackerel and herring, is a good source of vitamin D3.

• Egg yolks: Egg yolks contain a small amount of vitamin D3.

• Enriched products: Some foods, such as milk, yogurt, juice and breakfast flakes, are enriched with vitamin D.

• Mushrooms: Some mushrooms grown under the influence of UVB radiation contain vitamin D2.

C. Vitamin D additives:

Vitamin D additives are an effective way to increase the level of vitamin D in the blood, especially for people who do not get enough vitamin D from the sun or from food.

• Types of additives: Vitamin D additives are available in two main forms: vitamin D2 (ergocalciferol) and vitamin D3 (cholegalciferol). Vitamin D3 is usually considered more effective than vitamin D2 in an increase in level 25 (OH) D in the blood.

• Dosage: The recommended daily dose of vitamin D depends on the age, state of health and level of vitamin D in the blood. In general, it is recommended to take 600-800 IU vitamin D per day to maintain the normal level of vitamin D. People with vitamin D deficiency may require a higher dose, up to 2000-4000 IU per day, under the supervision of a doctor.

• Safety: Vitamin D is considered safe when taking recommended doses. However, taking too high doses of vitamin D (more than 4000 IU per day) can lead to hypervitaminosis D, a state characterized by an increased level of calcium in the blood, nausea, vomiting, weakness and other symptoms.

IV. Risk factors for vitamin D deficiency and recommendations for various population groups

Some groups of the population are at risk of vitamin D deficiency and need special attention.

A. Risk factors:

• Elderly people: Older people have a reduced ability to synthesize vitamin D in the skin and may have a violation of vitamin D absorption in the intestines.

• People with dark skin: People with dark skin need a greater time to stay in the sun to synthesize a sufficient amount of vitamin D.

• People living in the northern latitudes: People living in the northern latitudes have fewer opportunities for the synthesis of vitamin D from the sun, especially in the winter months.

• Oboor people: Vitamin D is a fat -soluble vitamin, so in people with obesity more vitamin D is stored in adipose tissue, which makes it less accessible to the body.

• People with certain diseases: People with diseases such as celiac disease, Crohn’s disease, cystic fibrosis, liver and kidney diseases, may have a violation of absorption or metabolism of vitamin D.

• Pregnant and lactating women: Pregnant and lactating women need more vitamin D more to maintain bone health and fetal development.

B. Recommendations for various population groups:

• Babies and children: It is recommended to give vitamin D additives, starting from the first days of life, in a dose of 400 IU per day. Children over 1 year old are recommended to receive 600 IU vitamin D per day from food and/or additives.

• Elderly people: Older people are recommended to take 800-1000 IU vitamin D per day to maintain the health of bones and muscles.

• Pregnant and lactating women: Pregnant and lactating women are recommended to take 600-800 IU vitamin D per day.

• People with risk factors: People with risk factors of vitamin D deficiency are recommended to consult a doctor to determine the optimal dose of vitamin D.

V. The interaction of vitamin D with other substances and drugs

Vitamin D can interact with some other substances and drugs, affecting their absorption, metabolism and effectiveness.

• Calcium: Vitamin D promotes calcium absorption in the intestines. Reception of vitamin D along with calcium can improve bone health and reduce the risk of fractures.

• Magnesium: Magnesium is necessary to activate vitamin D in the body. Magnesium deficiency can reduce vitamin D.

• Vitamin K2: Vitamin K2 helps to direct calcium into the bones and teeth, preventing its deposition in soft tissues. Vitamin D, together with vitamin K2, can improve bone health and reduce the risk of cardiovascular diseases.

• Glucocorticoids: Glucocorticoids can reduce vitamin D in the blood and increase the risk of osteoporosis. People taking glucocorticoids may require a higher dose of vitamin D.

• Anticonvulsants: Some anticonvulsants can reduce vitamin D in the blood. People taking anticonvulsants may require a higher dose of vitamin D.

• Orlistat: Orlistat, a drug for the treatment of obesity, can reduce the absorption of fat -soluble vitamins, including vitamin D. It is recommended to take vitamin D. to take orlistat people.

VI. Prospects for vitamin D research

Studies of vitamin D continue, and scientists study its role in various aspects of health, including the prevention and treatment of chronic diseases.

• Cancer: Studies show that vitamin D can play a role in the prevention of some types of cancer, including colon cancer, breast cancer and prostate cancer.

• Cardiovascular diseases: Studies show that vitamin D deficiency can be associated with an increased risk of cardiovascular disease, such as hypertension, coronary heart disease and stroke.

• Autoimmune diseases: Studies show that vitamin D can help reduce the risk of autoimmune diseases such as multiple sclerosis, type 1 diabetes and rheumatoid arthritis.

• Infectious diseases: Studies show that vitamin D can play a role in the prevention and treatment of infectious diseases, such as flu and pneumonia.

• Cognitive functions: Studies show that vitamin D deficiency can be associated with cognitive disorders and dementia.

Future studies of vitamin D are likely to be focused on determining the optimal levels of vitamin D for health, studying its role in the prevention and treatment of various diseases and developing new strategies to increase the level of vitamin D in the blood.

VII. The importance of consulting a doctor

It is important to consult a doctor before starting to take vitamin D additives, especially if you have any diseases or take any medication. The doctor can determine the optimal dose of vitamin D for you and control your vitamin D level in the blood. Self -medication can be dangerous for your health.