Vitamin D
Vitamin D is known as a fat-soluble vitamin, which is different from other vitamins that the body can manufacture in the skin through exposure to the medium of the sun , Vitamin D passes through two stages to activate it, the first liver, and the second in the kidneys Vitamin D works in the body after activating it as a steroid hormone called dihydroxyl coli, such as cephalicol (calcitriol). It plays an important and essential role in improving bone health and calcium balance in the body , And we will talk in this article about the importance of vitamin D in the human body and the effect of lack of it.
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 |
Importance of vitamin D to the human body
As mentioned above, vitamin D works in the body as a steroid hormone. It functions by interacting with its receptors in cell walls and intentions. It affects the process of gene replication in different tissues. Vitamin D affects more than 50 genes. Gene Gene Link Protein for Calcium , And vitamin D functions include:
- The balance of calcium and phosphorus in the body, which is the most prominent functions, as it stimulates the composition of calcium-binding protein in the wall of the intestine, which absorbs it, and contributes to the absorption of calcium also by stimulating the channels of calcium absorption .
- Vitamin D plays an essential role in bone mineral deposition because it has a direct role in maintaining its concentrations in the blood. In addition to its role in calcium absorption, it also increases the absorption of phosphorus and stimulates the kidneys to re-absorb them, thereby contributing to bone health .
- Vitamin D works with thyroid hormone and calcitonin hormone to maintain a constant level of calcium in the blood, and if the level of calcium rises hormone thyroid gland to stimulate the withdrawal of calcium from the bones and the elimination of phosphorus in the urine, and if the level of calcium in the blood rises hormone Calcitonin, which raises the rate of elimination of calcium in the urine, so the adequate amounts of vitamin D and calcium together maintain normal levels of calcium in the blood and prevent the rise of hormone thyroid gland, which causes calcium loss of bone and reduce the mass .
- Vitamin D plays an important role in cell differentiation, reproduction and natural growth in many tissues that include skin, muscle, thyroid gland, immune system Brain, nervous system, cartilage, pancreas and genitals Breast and colon, which prevents the abnormal growth of cells, which reduces the risk of cancer .
- Vitamin D plays an important role in the metabolic processes in the muscles affecting its strength and contraction, and causes lack of weakness in the muscles, especially the heart muscle .
- Beta cells in the pancreas need Vitamin D until the normal insulin secretion is made , And some studies found that the level of hormone calcitriol in the blood is inversely proportional to insulin resistance and that it plays a role in the prevention of type 2 diabetes .
- Many recent studies suggest a role for vitamin D in regulating the immune system and immune responses after research has found vitamin D receptors in its cells, thereby reducing the chance of immune system dysfunction that causes autoimmune diseases, such as type 1 diabetes and MS Inflammatory bowel disease And some rheumatic diseases of the nature of self-immunity .
Vitamin D deficiency
Vitamin D deficiency is a common health problem that affects a large number of people. Its deficiency causes a deficiency in the formation of calcium-binding proteins in the intestinal cells, thereby reducing the absorption of calcium. Vitamin D deficiency causes a secondary calcium deficiency even if the person is eating it in sufficient quantities. In children rickets disease while it causes bone Lin disease in adults , As well as more health effects of the lack of which we will talk about below.
Causes of vitamin D deficiency
Causes of vitamin D deficiency include:
- Insufficient exposure to sunlight .
- Dark skin color , Where people with darker skin need a longer period of exposure to the sun to get adequate amounts of vitamin D compared to their counterparts of light skin .
- Breastfeeding the mother’s milk without giving the baby vitamin D supplements .
- Some studies have found that obesity increases the chance of vitamin D deficiency by affecting the body’s absorption efficiency. This effect is highlighted if a person relies on natural dietary sources and is supported by vitamin D instead of exposure to sunlight .
- Diseases that reduce digestion and absorption of fat cause vitamin D absorption .
- The risk of developing vitamin D increases in the elderly due to poor skin capacity, poor liver and kidney capacity, and reduced exposure to sunlight and low intake of fortified milk, the main source of the human diet .
Effects of Vitamin D deficiency
Rickets disease
This disease occurs when not enough mineral deposits in the bones during the growth stage, and caused by vitamin D deficiency as mentioned above, and can be caused by lack of calcium or phosphorus, and include the following symptoms:
- Malformations in the formation and shape of the bones, so that the bones are weak and unable to carry the body weight or bear the pressures of daily exposure to the bones normally, resulting in stiffness in the bones of the legs, protrusions in the form of rosary in the bones of the rib cage, and the emergence of the bones of the chest, The front skull .
- Inflammation of the bones of the wrist and ankle 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 continuous cramping) that occurs 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 .
- Delayed appearance, deformation and weakness of teeth .
Osteoporosis
Bone marrow disease is the adult version of rickets, which is more common in women who do not get enough calcium and exposure to sunlight , The disease causes a lack of bone density and the appearance of semi-fractures in the bones, especially in the spine and the femur and humility, and muscle weakness, and the risk of fractures, especially in the bones of the pelvis and wrist , This disease can cause stiffness in the feet and curvature in the back .
Osteoporosis affects women of childbearing age who are not exposed to the sun adequately and lack adequate protection of calcium and vitamin D after pregnancy and frequent breastfeeding .
Osteoporosis
Osteoarthritis is a multicenter disease, the most common disease in women after menopause, but it can affect older men The lack of adequate vitamin D results in a loss of calcium in the bones, reducing their mass, making them more susceptible to fractures. A study found that half of women with osteoporosis and pelvic fracture in hospital had an undiagnosed vitamin D deficiency .
Other effects of Vitamin D deficiency
- Vitamin D deficiency was associated with depression .
- Some studies have found a link between vitamin D deficiency and weight gain .
- Research has found that vitamin D deficiency increases the body’s susceptibility to infection of viruses, respiratory bacteria and asthma .
- Some studies have found a link between vitamin D deficiency and increased risk of death from cardiovascular disease .
- Some studies have found a link between vitamin D deficiency and cognitive retardation in older adults .
- Some studies have found a link between vitamin D deficiency and increased cancer risk .
Sources of Vitamin D
Exposure to sunlight is the main source of access, while food sources are generally not considered adequate , And exposure to sunlight for 10-15 minutes on sunny days two to three times a week , While those with darker skin need longer periods .
As for its sources of food, fish liver oils are the highest, and it is found in small amounts in butter, cream, egg yolks, liver, , Vitamin D can be obtained from its dietary supplements And fortified foods such as juices, breakfast cereals, milk, and margarine .
Mother’s milk, unprocessed bovine milk is a weak source of vitamin D, and the baby who breastfeeds breast milk should be given vitamin D supplements under the supervision of a doctor, while milk for the infant (formula milk) is always fortified with vitamin D so that it does not need Children who depend on it for their dietary supplements .