Vitamin D, among other nutrients, plays a key role in the proper functioning of our bodies. Besides its important role during the growth stage in children and the maintenance of bones and teeth, it is also necessary for the normal functioning of the Immune System, which acts against external agents.
Vitamin D is also known as “the vitamin of the sun“, since its production depends mainly on sunlight. It is for this reason that its levels are affected by a lack of exposure to the sun, the season, lifestyle or latitude, among other factors.
Causes of vitamin D deficiency
Food
Infants and children are most vulnerable to vitamin D deficiency caused by not getting enough vitamin D from food. This is because breast milk contains small amounts of vitamin D, and most infant formulas do not contain sufficient amounts of vitamin D either. For adults, it is often the result of not paying attention to their diet.
Insufficient exposure to sunlight.
Vitamin D is one of the vitamins that the body can produce naturally. Approximately 50-90% of the vitamin D present in the body is produced in the skin. However its manufacturing process requires exposure of the skin to sunlight. Therefore, not being exposed to enough sunlight at the right time often results in a decrease in the level of vitamin D being manufactured in the body.
Kidney and liver diseases
The kidneys and liver contain many important enzymes, including those involved in the process of producing vitamin D in the body or converting it into an effective form. Thus, the presence of a health problem in the kidneys or liver, such as cirrhosis or kidney failure, can lead to a decrease in the body’s manufacture of vitamin D or failure to convert it into an effective form.
Taking certain medications
There are some medications that increase the metabolism of vitamin D in the body. Vitamin D is metabolised and broken down in the body by a series of liver enzymes called cytochrome B450 enzymes and therefore taking drugs that activate these enzymes leads to an increase in the rate of vitamin D breakdown and elimination, leading to a decrease in its levels in the blood.
Symptoms of vitamin D deficiency
People with mild or moderate vitamin D deficiency may not have any symptoms. But in cases of severe vitamin D deficiency, there are a variety of symptoms and health problems. Symptoms of vitamin D deficiency include:
- General tiredness and weakness, increased feelings of drowsiness or lethargy.
- Mood swings, anxiety and, in severe cases, the individual may suffer from depression.
- Hair loss, weight gain or difficulty losing weight.
- Muscle, bone and joint pain, especially back pain.
- Slow healing of wounds caused by injury or surgery.
- poor dental structure, especially in children
Immune function, lungs and vitamin D
The connection between vitamin D levels and the action of the immune system in the respiratory tract against external factors has been discovered. Besides its important role in bones, vitamin D contributes to normal immune functioning. It acts on the innate immune system, natural defence cells and proteins, thus helping the immune system to function properly against possible microbial agents.
In the respiratory tract, it can modulate defence mechanisms, specifically the cough response. The secretion of mucus from the tissue covering the bronchi, which helps maintain the integrity of lung tissue. Apart from the positive effects of this vitamin on innate immune function, it also has a positive effect on the adaptive immune response, which activates the cells responsible for recognising external agents inhaled through the respiratory tract.
Where to find vitamin D
The body can manufacture sufficient amounts of vitamin D. However a person may not get enough if he or she is not sufficiently exposed to sunlight. Or if the body has difficulty absorbing vitamin D. All of which leads to a deficiency in it, and the onset of the symptoms that occur. Among the foods rich in vitamin D: oily fish, egg yolks, fortified cereals, beef liver, cod liver oil…
- Chao Yang, MD, PhD. et al. Efficacy of High-Dose Vitamin D Supplementation as an Adjuvant Treatment on Pneumonia: Systematic Review and a Meta-Analysis of Randomized Controlled Studies. Nutrition in Clinical Practice. Sep, 2020.
- Kujach, S. et al. The Effect of Vitamin D3 Supplementation on Physical Capacity among Active College-Aged Males. Nutrients. Jun, 2020.
- Poorna R. et Biswal, N. Respiratory infections: Role of Vitamin D and surfactant proteins A and D. Sep, 2020.
- Schrumpf, J. et al. Impact of the Local Inflammatory Environment on Mucosal Vitamin D Metabolism and Signaling in Chronic Inflammatory Lung Diseases. Jul, 2020.
