Vitamin D
Vitamins are essential nutrients of the human body, organic compounds that are naturally found in foods and which the body needs in small quantities to carry out its normal functions. The body can not manufacture them or manufacture enough to meet their needs. Therefore, they need to be obtained from external sources. . Vitamin D is a fat-soluble vitamin that is different from other vitamins and can be manufactured in the body through the average exposure to sunlight from a cholesterol-induced primary substance. It acts as a steroid hormone called dihydroxyl coli, such as cephalicol (calcitriol) Bone health and calcium balance in the body.
Daily needs of vitamin d
The following table shows the daily requirements of vitamin D by age group:
| Age group | Daily needs (microgram / day) | Upper limit (microgram / day) |
|---|---|---|
| Infants 0-6 months | 10 | 25 |
| Infants 6-12 months | 10 | 38 |
| Children 1-3 years | 15 | 63 |
| Children 4-8 years | 15 | 75 |
| 5-50 years | 15 | 100 |
| 51-70 years | 20 | 100 |
| 71 years and over | 15 | 100 |
| Pregnant and nursing | 15 | 100 |
Places of Vitamin D
- Dietary supplements containing vitamin D
- Most studies have found that exposure to the sun for 10 to 15 minutes on sunny days two to three times a week is sufficient to supply the body with vitamin D needs. , Dark skin owners may need more time to get sun exposure.
- Vitamin D is found in animal products, especially fish liver oil. It is also found in small amounts of butter, cream, egg yolk and liver. It can also be obtained from juices, breakfast cereals and margarine.
- Breast milk and cow’s milk are a weak source of vitamin D, so milk is often fortified and should be given to a child who breastfeeds as a doctor. People who are not exposed to sunlight should be careful to drink two cups of vitamin D-fortified milk daily.
- Vitamin D is well-established and does not lose food when exposed to heat or prolonged storage.
Vitamin D functions in the body
Vitamin D works primarily as a steroid hormone and has binding proteins in the blood. It works by interacting with vitamin D receptors in cell walls and intentions, influencing gene replication in different tissues. It affects more than 50 genes, including the calcium-binding protein gene, His functions include:
- Calcium and phosphorus balance in the body. These are the most important functions of vitamin D in the body, as it stimulates the formation of calcium-binding protein in the intestinal wall to increase calcium absorption. It also helps to absorb calcium by stimulating calcium channels to absorb it.
- Vitamin D plays a key role in the deposition of minerals in the bones by maintaining its concentration in the blood.
- Vitamin D also increases the absorption of phosphorus and also re-absorbs calcium and phosphorus in the kidneys.
- The thyroid hormone and calcitonin are maintained at the level of calcium in the blood. If the blood calcium level drops, the thyroid gland increases the thyroid stimulating the withdrawal of calcium from the bones and the release of phosphorus in the urine, while if the level of calcium in the blood rises, the hormone calcitonin rises to increase the elimination rate Calcium in the urine, so vitamin D and calcium in sufficient quantities maintain normal levels of calcium in the blood and prevent hyperthyroidism and thyroid gland loss of calcium.
- Calcitriol plays an important role in cell differentiation, proliferation and normal growth in many tissues, including skin, muscle, thyroid gland, immune system, brain, nervous system, cartilage, pancreas, genitals, breast and colon, prevents abnormal growth of cells and thus reduces the risk of cancer.
- Vitamin D plays an important role in the prevention of rheumatic diseases that are characterized by autoimmune diseases.
- Plays an important role in metabolic processes in the muscles and affects the strength and constriction, and weakens the lack of muscles, especially the heart muscle.
- Some studies have found that the level of the hormone calcitriol in the blood is inversely proportional to the resistance of insulin and has a role in the prevention of diabetes type II.
- Many recent studies suggest the role of vitamin D in regulating the immune system after vitamin D receptors have been found in its cells, where immune system dysfunction is caused by type 1 diabetes, scleroderma and inflammatory bowel disease. Vitamin D regulates these responses.
- Recent research is studying several new roles for vitamin D in tissues previously unknown to vitamin D.
Vitamin D absorption, transport and storage
50% of vitamin D is absorbed with fat by negative circulation to the intestinal cells that convert fat into the kilomycrons and enter vitamin D with it, which is then absorbed into the lymphatic system and then enters the plasma. Vitamin D, which is manufactured in the skin, enters the blood and travels to different tissues. The liver stores only a small amount of vitamin D.
Vitamin D deficiency
Vitamin D deficiency is a common health problem for a large number of people. It causes a decrease in the formation of calcium-binding proteins in the intestinal cells, which affects the absorption of calcium. Vitamin D deficiency causes calcium deficiency even if it is taken in sufficient quantities. Vitamin D deficiency causes rickets in children and osteoporosis in adults.
Causes of vitamin D deficiency
- Insufficient exposure to sunlight, as in some countries that lack sunlight or a lifestyle that prevents a person from being exposed to sunlight.
- Dark skin.
- Breastfeeding the mother’s milk without giving the child vitamin D supplements.
- Some studies have found that obesity reduces the absorption of vitamin D, so if a person relies on natural sources of nutrients rather than exposure to sunlight, obesity can cause vitamin D deficiency.
- Digestive diseases that cause poor digestion and absorption of fat also cause a decrease in vitamin D absorption.
Symptoms Of Vitamin D Deficiency
Ricks
A disease that occurs due to lack of deposition of sufficient quantities of minerals in the bones during the growth stage, and caused by vitamin D deficiency as can be caused by lack of calcium and phosphorus deficiency, and its symptoms include:
- The bones become weak and can not carry the weight of the body or bear the usual pressure, resulting in a hardness in the bones of the legs at the age of the child to stand and walk, and produces protrusions in the form of rosary in the bones of the rib cage, and the emergence of the bones of the chest Or so-called chest of the pigeon, and the protrusion of the skull of the front.
- Inflammation of the wrist and ankle occurs due to the failure of these areas in the deposition of minerals, and thus continue to grow.
- Pain in the bones.
- Softness in the muscles.
- Muscle spasm (constriction and constant cramping) due to lack of calcium.
- Elevated level of alkaline phosphatase enzyme in the blood due to its release from the cells of the bone marrow.
- The appearance of teeth in children with vitamin D deficiency may also be delayed and dental abnormalities and weakness may occur.
Osteoporosis
The disease causes a decrease in bone density and the appearance of fractures in the bones, especially in the spine, femur and humerus, with weakness in the muscles, and raises the risk of fractures especially in the bones of the pelvis and wrist, especially affects women who lack calcium and insufficient exposure To the sun, it may cause stiffness in the feet and curvature in the back.
Other symptoms of Vitamin D deficiency
- Vitamin D was found to be associated with depression, and vitamin D supplements were found to help people with depression.
- Some studies have found a link between vitamin D deficiency and increased body fat accumulation which contributes to obesity and weight gain.
- Research has found that vitamin D deficiency increases the susceptibility of the body to infection of viruses and respiratory bacteria, has a role in asthma and may play a role in its treatment.
Vitamin D toxicity
Vitamin D overdose, which is high in excess of the daily limit, causes toxicity. This toxicity produces dietary vitamin D intake, not exposure to the sun or its natural sources, and increases the risk of high calcium and phosphorus levels in the blood,
- Soft tissue calcification such as: kidney, heart, lungs, and tympanic membrane in the ear which may cause deafness (deafness), and include symptoms headache and nausea
- Kidney stones and calcification in artery walls may cause high risk in the arteries of the heart and lungs that can cause death.
- Vitamin D toxicity in infants causes gastric ulcers, osteoporosis, and delayed growth. Vitamin D supplementation should only be taken as a doctor’s prescription and should be kept out of the reach of children.