THE importance of vitamin D for bone health is well known to everyone, but did you know that it also acts in other areas of our body? Yes, this nutrient is involved in several functions and it is essential to maintain its proper levels in the body.
Low exposure to solar radiation and malabsorption can trigger deficiency of Vitamin D. This problem can be solved with supplementation, which should only be done with a doctor's recommendation. Exaggerated levels can cause kidney problems, for example.
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How important is vitamin D?
Vitamin D has a number of important functions in our body, the main one being its role in metabolism of calcium and in bone formation. This vitamin ensures, for example, that our intestines absorb a greater amount of calcium and that our kidneys increase the reabsorption of this mineral, thus providing stronger bones.
In situations of vitamin D deficiency, our skeletal system can be affected. THE lack ofwow vitamin can cause rickets in children as well as osteomalacia in adults, two bone mineralization defects. In rickets, the child has growth retardation and skeletal deformities; in osteomalacia, the adult has a low bone mineral density.
Vitamin D's actions, however, go beyond calcium metabolism. Here are some of the functions that can be attributed to this vitamin:
- Acting in immune system – this vitamin seems to act in the regulation and differentiation of defense cells, such as lymphocytes.
- Reduction of the risk of developing some types of neoplasms, as it acts in the cell differentiation process and inhibits proliferation.
- Acting in the control of blood pressure and cardiac function.
- Stimulation of insulin secretion, thus ensuring blood glucose control. Studies suggest that this vitamin may bring benefits in the treatment and prevention of diabetes mellitus.
- Prevention of autoimmune diseases, and it is also possible to use it in the treatment of these health problems.
Recently, vitamin D was identified as an important ally in preventing COVID-19, however no study has proven the benefit of using this vitamin for prevention or treatment.
According to the clarification note from the Brazilian Society of Endocrinology and Metabolism (SBEM) and the Brazilian Association of Bone Evaluation and Osteometabolism (ABRASSO), "there is, to date, no approved indication for the prescription of vitamin D supplementation aiming at effects beyond the bone health”. It is also important to highlight that incorrect supplementation can damage the body, as we will see later.
Vitamin D sources
Unlike other known vitamins, vitamin D is not acquired primarily through food. The main source of this nutrient is the synthesis in the skin., which depends on ultraviolet B radiation. This radiation reaches our skin and transforms 7-dehydrocholesterol (a skin precursor of vitamin D) into pre-vitamin D3 and, later, into vitamin D3. This enters the bloodstream and goes towards the liver and kidney, where it undergoes changes that make it active.
When it comes to food, vitamin D sources are limited. It can be found at fatty fish, eggs and dairy products. It is noteworthy that the diet accounts for only 20% of our needs for this vitamin. As a large part of its production depends on solar radiation, it became known as “vitamin of the sun”.
Read too:Importance of calcium in the body
Optimal Vitamin D Levels
There is a lot of debate about the ideal amount of vitamin D that should be present in our body. According to the publication “Official Position of the Brazilian Society of Clinical Pathology/Laboratory Medicine and the Brazilian Society of Endocrinology and Metabolism”, the desirable value for the healthy population up to 60 years of age is above in 20 ng/ml.
Some people experience a deficiency of this vitamin, which can be caused by a variety of factors. Insufficient sun exposure is one of them, especially in the elderly and people with diseases that make it difficult for them to move around, since they are less exposed to the sun. In addition, problems related to malabsorption, use of certain medications, such as anticonvulsants, obesity and increased skin pigmentation are also factors that favor a lower Vitamin D absorption.
In case of deficiency, the doctor will assess the real need for supplementation. It is important to emphasize that supplementation done improperly can cause damage to the body. Despite being beneficial, this vitamin in excess can cause intoxication. One of the consequences of high levels of vitamin D is called hypercalcemia, which can even cause loss of kidney function. In addition, bone loss can also occur, as this vitamin favors the activity of osteoclasts, which act in bone remodeling.
By Vanessa Sardinha dos Santos
Biology teacher
Source: Brazil School - https://brasilescola.uol.com.br/saude-na-escola/importancia-da-vitamina-d.htm
