Vitamin D
Vitamin D is a fat-soluble vitamin that is naturally present in a few foods, a vitamin that activates the body to act as a hormone (calciferol). Vitamin D can be obtained from nature through exposure to the sun, so it is also called the sun’s vitamin, Of food is as basic as other vitamins, but it must be taken care of with adequate exposure to sunlight.
Vitamin D functions in the body
Vitamin D works mainly as a steroid hormone called dihydroxyl coli, such as cephirol or calcitriol. It works by interacting with vitamin D receptors in cells, affecting gene replication. It affects more than 50 genes, including the calcium-binding protein gene, What follows:
- The most important function of vitamin D in the body is its role in the balance of calcium and phosphorus. It stimulates the formation of the calcium-binding protein in the intestinal wall, which absorbs it. It also stimulates calcium channels to absorb it. It also contributes to the absorption of phosphorus and re-absorbs both calcium and phosphorus in the kidneys. To its role with the hormone thyroid gland in stimulating the exit of calcium from the bones and put phosphorus in the urine if the level of calcium in the blood, and this mechanism plays vitamin D its primary role in maintaining the concentration of calcium and phosphorus in the blood to allow bone deposition, Li has sufficient amounts of vitamin D and calcium maintains the level of calcium in the blood, and prevents the high level thyroid hormone thyroid gland which stimulates the calcium outflow of the bones.
- Calcitriol plays an important role in the normal growth, differentiation and reproduction of cells in many tissues of the body, such as skin, muscles, immune system, thyroid gland, brain, nervous system, genitals, cartilage, pancreas, breast and colon. It also prevents abnormal growth of cells, reducing the risk of cancer.
- Vitamin D plays an important role in muscular metabolic processes, affecting its strength and contraction. Its deficiency causes weakness in the muscles, especially the heart muscle.
- Some studies have found that the level of vitamin D (calcitriol) in the blood is inversely proportional to insulin resistance and reduced risk of type 2 diabetes.
- Many recent studies have found a role for vitamin D in regulating immune system responses. Immune system responses occur in some autoimmune diseases, such as type 1 diabetes, scleroderma, inflammatory bowel disease, and rheumatism caused by autoimmune disorders.
Daily needs of vitamin d
The Institute of Medicine has raised the daily needs and the highest vitamin D intake. The following table presents the new values 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 |
Symptoms Of Vitamin D Deficiency
Symptoms of vitamin D deficiency vary by age. In each age, the decrease in the incidence of a particular disease causes a decrease in the absorption of calcium. Vitamin D deficiency causes secondary calcium deficiency even if the amount of calcium intake is sufficient. D. Teenagers do not reach the highest bone mass their bones can reach. It also causes rickets in children and osteoporosis in adults.
Ricks
Bone growth is delayed when you do not get enough calcium. This is achieved in children who do not get enough vitamin D, where their bones grow weak and may be affected by some deformities, and therefore the bones of the legs bowing because of their inability to tolerate body weight and bear the usual stresses, The appearance of protrusions in the chest bones in the form of rosary due to imbalance in the association of bone cartilage, and the emergence of the bones of the head of the front, and constant muscle spasm (muscle spasm) due to lack of calcium (Hypocalcemic tetany) with pain in the bones and muscles, and the growth of teeth delayed in children People with rickets m The possibility of weak growth and the emergence of distortions in them.
Osteoporosis
Vitamin D deficiency in adults causes a general lack of bone mass and is similar to fractures, especially in the bone of the spine, femur, and humerus. Bone density decreases to the point of curvature of the feet and curvature of the back. It also causes muscle weakness and increases the risk of fractures, especially in the wrist and pelvis.
Osteoporosis
Osteoarthritis is more common in postmenopausal women, a multi-factor disease in which bone loss occurs. Lack of adequate vitamin D causes calcium loss of bone, which increases the risk of fractures. Women with osteoporosis and pelvic fractures in the hospital reported that half of them had vitamin D deficiency.
Other effects of vitamin D deficiency
- Depression: Many studies have found a link between vitamin D deficiency and high rates of depression, and also found that taking dietary vitamin D supplements contributes to the treatment of depressed patients who lack it.
- Fat accumulation and obesity: Many studies have found that vitamin D deficiency may increase the chance of accumulation of fat in the body and obesity.
- High risk of some cancers.
- Increased cognitive retardation opportunity in older persons.
- High risk of death from cardiovascular disease.
- High risk of bacterial and viral respiratory infections.
- The increased risk of asthma was also found to be associated with severe asthma in children.
- Vitamin D deficiency increases the risk of high blood pressure.
- Vitamin D deficiency increases the risk of death for any reason.
- Vitamin D deficiency raises the chance of high cholesterol.
Causes of vitamin D deficiency
- Insufficient exposure to sunlight.
- Frequent use of sunscreen to avoid damage, which include the appearance of early wrinkles and increased risk of skin cancer.
- The risk of vitamin D deficiency increases in people with darker skin.
- The risk of vitamin D deficiency increases with age due to poor capacity of the skin, liver and kidneys to convert vitamin D to its active form, as well as the lack of aging and exposure to sunlight, and lack of vitamin D-fortified milk, which is the main dietary source.
- Inability to absorb vitamin D well because of gastrointestinal problems, such as Crohn’s disease, cystic fibrosis and celiac disease.
- The risk of vitamin D deficiency increases in cases of obesity. Vitamin D in the fat is stored in the fatty tissue, and the higher the fat tissue, the more vitamin D is withdrawn from the blood.
- Vitamin D deficiency is high in some health conditions, such as heart disease and chronic obstructive pulmonary disease.
Food Sources of Vitamin D
- The whale liver oil is the richest dietary source of vitamin D.
- Vitamin D is found in simple and varying amounts of egg yolk, butter, cream and liver.
- Vitamin D can be obtained from fortified foods, such as fortified breakfast cereals, juices and fortified milk.
- Breast milk is a poor source of vitamin D, so babies should be given vitamin D under the supervision of a doctor. Industrial infant formula is usually supported and children do not need vitamin D supplements.
Treatment of vitamin D deficiency
Vitamin D deficiency should be treated with more diet, supplements and sun exposure. Vitamin D deficiency should be treated under the supervision of a doctor. Care should be taken not to take dietary vitamin D supplements without doctor’s supervision. This can result from vitamin toxicity. D in high doses.
Side effects of vitamin D supplementation and toxicity
Most of the time vitamin D is not accompanied by side effects if taken with the dose recommended by the doctor, but the very large quantities of it cause high level of calcium and phosphorus in the blood, which leads to the deposition of calcium in soft tissues such as the heart, lungs, kidneys and the dorsal membrane in the ear, This can be dangerous if it occurs in the main arteries and may cause death. Vitamin D poisoning in infants causes intestinal dysfunction, delayed growth and bone weakness.
Symptoms of vitamin D toxicity include general body weakness, fatigue, drowsiness, headaches, loss of appetite, dry mouth, metallic taste in the mouth, vomiting and nausea.