Vitamin D is a fat-soluble vitamin required by the body for bone development and maintenance. It helps in the absorption of calcium, magnesium, and phosphate. The active form of vitamin D is known as 1,25 dihydroxycholecalciferol (calcitriol).
Blood tests generally detect the precursor of calcitriol known as 25 hydroxycholecalciferol (calcidiol). Vitamin D is formed from cholesterol in the body. Cholesterol is first converted to 7 dehydrocholesterol, followed by its conversion to cholecalciferol before being converted to calcidiol and calcitriol.
This conversion from cholesterol to vitamin D is dependent on sunlight, so this vitamin is also known as the sunshine vitamin. A healthy level of 25-hydroxyvitamin D greater than 30 ng/mL in the blood.
Deficiency of this vitamin can lead to osteomalacia and rickets in children and osteomalacia in adults. Rickets was eradicated after the introduction of vitamin D-fortified milk. Moderate deficiency is associated with osteoporosis and bone fragility.
Multiple studies have shown an association between vitamin D deficiency and the occurrence of cancer, cardiovascular disease, type 2 diabetes mellitus, autoimmune disease, chronic diseases, and even depression. Around one billion people in the world are estimated to be deficient in the vitamin. Sedentary adults may require about 2000 IU of cholecalciferol daily.
Symptoms of Vitamin D Deficiency
As vitamin D plays an important role in immunity, mental health, bone development, maintenance, and mineral balance, the common symptoms of its deficiency generally involve several conditions as discussed below:
Frequent Infections
Vitamin D regulates the immune cells of the body, which ward off harmful pathogens. Deficiency of the vitamin is often found in people with chronic occurrences of respiratory tract infections, such as colds, bronchitis, and pneumonia.
Recently, vitamin D deficiency was found to be linked to an increased risk of COVID-19 and related symptoms. Low vitamin D was also found to be associated with post COVID symptoms (long COVID).
Fatigue & Sleep Issues
Some studies have linked vitamin D deficiency with fatigue. In this case, people generally overlook the deficiency of the vitamin, as fatigue is also associated with other problems.
Deficiency of this vitamin can lead to poor sleep quality and shorter sleep duration. Supplementation of cholecalciferol often helps people with sleep issues.
Joint Pain & Back Pain
Vitamin D helps maintain bone density by aiding in the absorption of calcium in the body. Several studies have found that people with chronic bone and joint conditions, such as arthritis, joint pain, and mobility issues tend to be deficient in the vitamin. Further studies are required for all bone-related conditions, though.
Mental Health Issues and Depression
Alhough research related to the role of vitamin D and depression is in its initial stages, preliminary studies have shown that the severity of depression might be associated with low levels of the vitamin.
Decreased Bone Density and Bone Loss
Loss of calcium and other minerals leads to low bone mineral density. Vitamin D plays a crucial role in the absorption and maintenance of the building blocks of bones, which mainly comprise of calcium. Supplementation of the vitamin is often prescribed to individuals with low bone mineral density.
Hair Thinning
Alopecia areata, a common condition characterized by severe hairfall, is known to be associated with the deficiency of cholecalciferol.
The exact mechanism of the phenomenon is not known, and further research is required to prove these claims. Supplementation of the vitamin has been found to help decrease the rate of hair loss.
Causes of Vitamin D Deficiency
Conditions related to upper intestinal tract, including celiac disease, short bowel syndrome, inflammatory bowel disease (IBD), and chronic pancreatic insufficiency can decrease the amount of vitamin D absorbed in the intestine.
More than 50% of the vitamin D in the body is made from cholesterol in the presence of sunlight. Decreased exposure to the sun can lead to a deficiency of the vitamin. Chronic liver conditions, including cirrhosis, can also affect the synthesis of active calcitriol in the body.
Treatment of Vitamin D Deficiency
Consumption of cholesterol from natural foods can prevent the deficiency of cholecalciferol by providing adequate precursor molecules for the synthesis of the vitamin.
Meat, egg yolks, fatty fish, and dairy contain healthy good cholesterol. Some plant-based foods contain ergocalciferol, which is a precursor of cholecalciferol, known as vitamin D2. Vegans and vegetarians can opt for fortified cereals and products to get their share of the same.
Takeaway
Consuming more vitamin D-rich foods may help boost the level of the vitamin in the body. Supplementation should only be taken under the supervision of a certified health professional. A balanced diet is essential to get all necessary vitamins and minerals.