Vitamin D Deficiency: Causes, Symptoms, Diagnosis, Treatment, and Prevention
As a fat-soluble vitamin, Vitamin D is responsible for many bodily functions, including calcium absorption and bone health. Vitamin D is naturally produced by the skin when exposed to sunlight, but it can also be obtained from food and supplements.
Causes of Vitamin D Deficiency
Vitamin D deficiency occurs when the level of vitamin D in the blood is too low. This can happen for various reasons, such as:
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Lack of sun exposure: People who live in areas with less sunlight, wear sunscreen or clothing that covers most of the skin, or have darker skin may not produce enough vitamin D from the sun.
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Poor diet: People who do not eat enough foods that contain vitamin D, such as fatty fish, egg yolks, cheese, and fortified milk, may not get enough vitamin D from their diet.
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Malabsorption: People who have certain medical conditions that affect the absorption of fat-soluble vitamins, such as celiac disease, Crohn’s disease, or cystic fibrosis, may not absorb enough vitamin D from their food or supplements.
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Kidney or liver disease: People who have chronic kidney or liver disease may not be able to convert vitamin D into its active form in the body.
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Obesity: People who have a body mass index (BMI) of 30 or higher may have lower levels of vitamin D in their blood, as vitamin D is stored in fat tissue and may not be released into the bloodstream.
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Age: People who are older than 65 may have reduced ability to produce and use vitamin D in the body.
Symptoms of Vitamin D Deficiency
Vitamin D deficiency can cause various symptoms, depending on the severity and duration of the deficiency. Some of the common symptoms include:
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Low vitamin D levels can result in osteomalacia (softening of the bones) in adults and rickets (deformities of the bones) in children.
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In addition to affecting muscle function, vitamin D plays an important role in the contraction and function of muscles. Low levels of vitamin D, especially in the legs and arms, can cause muscle aches, cramps, and weakness.
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Low levels of vitamin D may lead to fatigue, low mood, or depression. Vitamin D produces serotonin, a neurotransmitter that regulates mood, sleep, and appetite.
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It is common for infections and illnesses to occur: Vitamin D aids the immune system in fighting bacteria, viruses, and other pathogens. Low levels of vitamin D can impair the immune system, increasing the likelihood of infection, such as colds, flus, and respiratory infections.
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As Vitamin D is involved in the growth and repair of cells, low levels of vitamin D may also cause loss of hair, thinning, or brittleness, as well as skin problems, like dryness, itching, or eczema.
Diagnosis of Vitamin D Deficiency
The main form of vitamin D in the blood is 25-hydroxyvitamin D (25(OH)D), so a blood test can be used to diagnose vitamin D deficiency. 25(OH)D levels normally range between 20 and 50 nanograms per milliliter (ng/mL), although this may vary depending on the lab and reference values. A 25(OH)D level below 12 ng/mL is considered deficient, while a level between 12 and 20 ng/mL is considered insufficient.
Treatment of Vitamin D Deficiency
The amount of vitamin D required to treat vitamin D deficiency depends on the severity of the deficiency, the age, the weight, and the health status of the individual, as well as the amount of vitamin D consumed. Most adults need 600 international units (IU) or 15 micrograms (mcg) of vitamin D per day, while adults over 70 need 800 IU or 20 mcg. Some patients may need higher doses of vitamin D to correct the deficiency, as prescribed by their doctor. The upper limit of vitamin D intake for adults is 4,000 IU or 100 mcg.
Prevention of Vitamin D Deficiency
Vitamin D deficiency can be prevented by following these tips:
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You should get at least 15 minutes of sun exposure on your face, arms, and legs, two or three times a week, preferably between 10 a.m. and 3 p.m., when the sun is at its strongest. Use sunscreen if you are going to be in the sun for longer periods of time.
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The best way to get enough vitamin D in your diet is to eat foods that are rich in it or fortified with it, such as fatty fish, egg yolks, cheese, and fortified milk, cereal, orange juice, and yogurt.
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In case you are at risk of vitamin D deficiency or if you have a diagnosed deficiency, your doctor may recommend vitamin D supplements. Vitamin D3 (cholecalciferol) is the most effective form of vitamin D for the body, so choose supplements that contain it.
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You may need to check your vitamin D levels regularly, as advised by your doctor, if you have a history of vitamin D deficiency or a medical condition that affects your vitamin D metabolism. By doing so, you can prevent complications and adjust your vitamin D intake.
In addition to affecting bone health, muscle function, mood, immune system, and overall well-being, vitamin D deficiency is a common and treatable condition. Vitamin D deficiency can be prevented and treated by getting enough sun exposure, eating foods that contain vitamin D, and taking supplements as needed.
