Vitamin D: Why is it needed and where to get it

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

Section 1: Basics of vitamin D

Vitamin D, despite the name, is not so much a vitamin as a runner, that is, the predecessor of the hormone. It plays a crucial role in the regulation of the metabolism of calcium and phosphates, which directly affects the health of bones, teeth and muscles. However, its influence spreads much wider, affecting the immune system, cardiovascular system, nervous system and even mood.

1.1. Chemical structure and forms of vitamin D

There are two main forms of vitamin D: vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol).

• Vitamin D2 (ergocalciferol): It is produced by plants and mushrooms under the influence of ultraviolet radiation. Used in some enriched products and food additives.

• Vitamin D3 (cholecalciferol): It is synthesized in the skin of humans and animals under the influence of UVB-rays of sunlight. Also contained in animal products, such as oily fish, egg yolks and liver.

From a chemical point of view, both forms are steroids, but D3 is more effective in increasing the level of vitamin D in the blood and maintaining its stability. The body converts both forms into an active metabolite, calcitriol, which performs most of the functions of vitamin D.

1.2. Vitamin D

The transformation of vitamin D into an active form is a complex process that includes two stages of hydroxylation.

1. The first stage of hydroxylation: Occurs in the liver. Vitamin D2 or D3 turns into 25-hydroxyvitamin D [25(OH)D]also known as calciol or calcifediol. This metabolite is the main indicator of the level of vitamin D in the blood and is used to diagnose deficiency.

2. The second stage of hydroxylation: Occurs in the kidneys. 25 (oh) D turns into 1.25-dihydroxyvitamin D [1,25(OH)2D]also known as calcitriol. Calcitriol is a biologically active form of vitamin D and is associated with vitamin D (VDR) receptors in various body tissues.

The regulation of vitamin D metabolism is a complex system that includes parathormone (PTH), calcium and phosphates. With a low level of calcium in the blood, PTG stimulates the kidneys to the production of calcitriol. Calcitriol, in turn, increases calcium absorption in the intestines, reabsorption of calcium in the kidneys and mobilization of calcium from bones, thereby increasing the level of calcium in the blood.

1.3. Vitamin D functions in the body

Vitamin D plays a critical role in maintaining health and the normal functioning of many body systems.

• Bone health: Vitamin D provides the absorption of calcium and phosphates in the intestines necessary for the formation and maintenance of bone tissue. Vitamin D deficiency leads to rickets in children and osteomination in adults, characterized by weakness and deformation of bones. It also helps to reduce the risk of osteoporosis and fractures in the elderly.

• Immune system: Vitamin D plays an important role in the modulation of the immune system. It supports the function of immune cells, such as T-lymphocytes and B-lymphocytes, and helps to fight infections. A sufficient level of vitamin D can reduce the risk of developing autoimmune diseases.

• Muscle function: Vitamin D is necessary for the normal function of muscles. Vitamin D deficiency can lead to muscle weakness, pain and increased risk of falls.

• Cardiovascular system: Studies show that vitamin D deficiency is associated with an increased risk of cardiovascular disease, such as hypertension, heart failure and stroke. Vitamin D can regulate blood pressure, improve endothelium function and reduce inflammation.

• Nervous system: Vitamin D plays a role in the development and functioning of the nervous system. Vitamin D deficiency can be associated with an increased risk of depression, cognitive disorders and neurodegenerative diseases, such as Alzheimer’s disease.

• Cellular regulation: Vitamin D is involved in the regulation of cellular growth and differentiation. Studies show that he can play a role in the prevention of certain types of cancer.

Section 2: The causes and consequences of vitamin D deficiency

Vitamin D deficiency is a common problem around the world, affecting people of all ages and ethnic groups.

2.1. Factors that contribute to vitamin D deficiency

There are many factors that can contribute to the deficiency of vitamin D.

• Insufficient stay in the sun: The synthesis of vitamin D in the skin depends on the effects of UVB-rays of sunlight. People living in high latitudes, with dark skin, spending most of the time in the room or wearing closed clothing are at increased risk of vitamin D deficiency. The use of sunscreens also blocks the synthesis of vitamin D.

• Insufficient consumption of vitamin D with food: Many foods do not contain a sufficient amount of vitamin D. Fatty fish (salmon, herring, mackerel), egg yolks, liver and enriched products such as milk, yogurt and cereals include.

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

• Obesity: Vitamin D is a fat -soluble vitamin, and in people with obesity more vitamin D accumulates in adipose tissue, which reduces its accessibility for the body.

• Age: With age, the ability of the skin to synthesize vitamin D decreases. The kidneys also become less effective in converting vitamin D into an active form.

• Reception of some drugs: Some drugs, such as glucocorticoids, anticonvulsants and drugs to reduce cholesterol, can reduce vitamin D.

• Genetic factors: Some genetic options can affect vitamin D metabolism and predispose to deficiency.

2.2. Symptoms of vitamin D deficiency

Symptoms of vitamin D deficiency can be non -specific and often go unnoticed.

• Fatigue and weakness: Constant fatigue and weakness are one of the most common symptoms of vitamin D.

• Bone pain and muscles: Vitamin D deficiency can cause bone pain, especially in the back, hips and legs. Muscle pains and weakness are also often found.

• Frequent infections: Vitamin D plays an important role in maintaining the immune system, and its deficiency can lead to increased susceptibility to infections, such as colds and flu.

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

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

• Depression and mood swings: Vitamin D deficiency can be associated with an increased risk of depression and mood swings.

• Increased risk of fractures: Vitamin D deficiency weakens the bones and increases the risk of fractures, especially in the elderly.

In children, vitamin D deficiency can manifest itself in the form of rickets, which is characterized by bone deformation, growth and development delay.

2.3. Diagnosis of vitamin D deficiency

Diagnosis of vitamin D deficiency is carried out by measuring level 25 (OH) D in the blood.

• Optimal level: 30-50 ng/ml (75-125 nmol/l)

• Failure: 20-29 ng/ml (50-72.5 nmol/l)

• Deficiency: Less than 20 ng/ml (less than 50 nmol/l)

The doctor may prescribe a blood test for vitamin D if you have symptoms of deficiency, risk factors or disease associated with vitamin D. deficiency.

Section 3: Vitamin D sources

Obtaining a sufficient amount of vitamin D is possible through sunlight, food and food supplements.

3.1. Sunlight

The synthesis of vitamin D in the skin under the influence of UVB rays is the main source of vitamin D for most people.

• The time of stay in the sun: For most people, there are enough 10-30 minutes of the sun in the middle of the day several times a week to ensure sufficient synthesis of vitamin D. However, the time of stay in the sun depends on various factors, such as the breadth, time of year, time of day, skin color and the use of sunscreen.

• Latitude: In high latitudes, the intensity of the UVB rays lower, especially in the winter months, which complicates the synthesis of vitamin D.

• Top of year: In the winter months, when the sun is lower above the horizon, less UVB rays reaches the surface of the earth.

• Times of Day: The intensity of UVB ra ra ra raves is the highest in the middle of the day.

• Skin color: People with dark skin need more time being in the sun to synthesize a sufficient amount of vitamin D, since the melanin, the pigment responsible for skin color, absorbs UVB ray.

• Sunscreen cream: Sunscreen with SPF 15 and higher blocks about 99% UVB rays and significantly reduces the synthesis of vitamin D.

It is important to remember the risk of skin cancer with a long stay in the sun. It is recommended to use sunscreen after 10-30 minutes of the sun or wear protective clothes.

3.2. Food

Some foods contain vitamin D, but their number is usually not enough to meet the daily need.

• Fat fish: Salmon, herring, mackerel, tuna and sardines – good sources of vitamin D. Wild salmon contains more vitamin D than grown.

• Egg yolks: Egg yolks contain a small amount of vitamin D. Chickens that receive food enriched with vitamin D carry eggs with a higher vitamin D.

• Liver: Beef liver contains vitamin D, but also contains a lot of cholesterol, so it should be consumed moderately.

• Enriched products: Some products, such as milk, yogurt, orange juice and cereals, are enriched with vitamin D.

In general, the consumption of products rich in vitamin D is an important part of a healthy diet, but it may not be enough to maintain the optimal level of vitamin D, especially in people with risk factors.

3.3. Food supplements

Food supplements with vitamin D 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 sunlight and food.

• Vitamin D2 (ergocalciferol): This is a plant form of vitamin D, which is used in some additives.

• Vitamin D3 (cholecalciferol): This is an animal form of vitamin D, which is more effective in increasing the level of vitamin D in the blood and maintaining its stability.

• Dosage: The recommended daily dose of vitamin D depends on the age, state of health and level of vitamin D in the blood. Adults are usually recommended to take 600-800 IU (international units) of vitamin D per day. People with vitamin D deficiency may require a higher dose, for example, 1000-5000 IU per day, under the supervision of a doctor.

• Toxicity: Taking too much vitamin D can lead to hypervitaminosis D, which is characterized by an increased level of calcium in the blood (hypercalcemia). Symptoms of hypervitaminosis D include nausea, vomiting, weakness, frequent urination and bone pain. In rare cases, hypervitaminosis D can lead to damage to the kidneys and heart. It is important not to exceed the recommended dose of vitamin D and consult a doctor before taking additives.

Section 4: Vitamin D and health of various population groups

The need for vitamin D and the risks of deficiency can vary depending on age, gender and health.

4.1. Children

Vitamin D plays a critical role in the growth and development of bones in children.

• Rakhite: Vitamin D deficiency in children can lead to rickets, which is characterized by bone deformation, growth of growth and development.

• Recommendations: The American Academy of Pediatrics recommends that all babies and children receive 400 IU vitamin D per day from birth. Breastfeeding infants should give additives with vitamin D, since breast milk usually does not contain enough vitamin D. children older than a year who do not receive enough vitamin D from food, and additives with vitamin D.

4.2. Pregnant and lactating women

Vitamin D is necessary for the health of the mother and fetus during pregnancy and breastfeeding.

• The risks of deficiency: Vitamin D deficiency during pregnancy can be associated with an increased risk of preeclampsia, gestational diabetes and premature birth.

• Recommendations: Pregnant and lactating women are recommended to take 600-800 IU vitamin D per day. In some cases, the doctor may recommend a higher dose.

4.3. Elderly people

With age, the skin ability to synthesize vitamin D decreases, and the kidneys become less effective in converting vitamin D into an active form.

• The risks of deficiency: Elderly people are at risk of vitamin D deficiency, which can lead to osteoporosis, fractures, muscle weakness and falls.

• Recommendations: Older people are recommended to take 800-1000 IU vitamin D per day. It is also important to ensure sufficient calcium consumption and engage in physical exercises to maintain bone health.

4.4. 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, since melanin absorbs UVB rays.

• The risks of deficiency: People with dark skin are at risk of vitamin D deficiency, especially in high latitudes and in the winter months.

• Recommendations: People with dark skin may need to take additives with vitamin D in order to maintain the optimal level of vitamin D in the blood.

4.5. People with obesity

Vitamin D is a fat -soluble vitamin, and in people with obesity more vitamin D accumulates in adipose tissue, which reduces its accessibility for the body.

• The risks of deficiency: Obesity people are at risk of vitamin D.

• Recommendations: Oboor people may need to take higher doses of vitamin D in order to maintain the optimal level of vitamin D in the blood.

4.6. People with certain diseases

People with certain diseases, such as Crohn’s disease, celiac disease, cystic fibrosis and kidney disease, are at increased risk of vitamin D. deficiency.

• Recommendations: People with these diseases need to regularly check the level of vitamin D in the blood and take additives with vitamin D under the supervision of a doctor.

Section 5: Recent studies and prospects

Studies of vitamin D continue, and new data appear constantly.

5.1. Vitamin D and cancer prevention

Some studies show that vitamin D can play a role in the prevention of some types of cancer, such as colon cancer, breast cancer and prostate cancer. However, the results of the studies are contradictory, and further research is necessary to confirm this connection.

5.2. Vitamin D and autoimmune diseases

Studies show that vitamin D can play a role in the prevention and treatment of autoimmune diseases, such as multiple sclerosis, rheumatoid arthritis and type 1 diabetes. Vitamin D can modulate the immune system and reduce inflammation, which can be useful for people with autoimmune diseases.

5.3. Vitamin D and Covid-19

Some studies have shown that vitamin D deficiency is associated with an increased risk of infection of the COVID-19 and a more severe course of the disease. However, further studies are needed to confirm this connection and determine whether the intake of vitamin D can reduce the risk of infection COVID-19 or improve the outcomes of the disease.

5.4. Vitamin D and cognitive functions

Studies show that vitamin D can play a role in maintaining cognitive functions and reducing the risk of cognitive disorders and neurodegenerative diseases such as Alzheimer’s disease.

5.5. New forms of vitamin D

New forms of vitamin D are developed, which can be more effective or have less side effects. For example, calciol (25 (OH) D) and vitamin D analogues are studied, which can be more quickly absorbed and active.

Section 6: Recommendations for maintaining the optimal level of vitamin D

Maintaining the optimal level of vitamin D is important for health and well -being.

• Be regular in the sun: Try to spend 10-30 minutes in the sun in the middle of the day several times a week.

• Use products rich in vitamin D: Include oily fish, egg yolks, liver and enriched products in your diet.

• Take additives with vitamin D: If you do not get enough vitamin D from sunlight and food, consider the possibility of taking additives with vitamin D.

• Check the level of vitamin D in the blood: Regularly check the level of vitamin D in the blood, especially if you have risk factors for deficiency.

• Consult a doctor: Consult a doctor to determine the optimal dose of vitamin D for you and discuss any questions or fears.

Compliance with these recommendations will help you maintain the optimal level of vitamin D and improve your health.