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Symptoms and causes for vitamin D deficiency

Are you experiencing fatigue, pain in your bones or weakness in your muscles? It’s possible that the vitamin D level in your body is lower than necessary. However, the symptoms of vitamin D deficiency can be subtle or even absent, making it more difficult to diagnose the problem on time. Months or even years could pass before any symptoms occur. At the same time, the low level of this vitamin is associated with a number of health problems.

What are the most common symptoms?


As there can be many different reasons that could cause fatigue, this symptom is often overlooked as a sign of vitamin D deficiency. Chronic fatigue can also lead to other consequences that can negatively impact a person’s quality of life.

Bone pain

Vitamin D plays a key role in the body’s ability to absorb calcium. A potential vitamin D deficiency can affect bone strength and cause back and lower back pain.

Muscle pain or weakness

This vitamin is associated with muscles’ ability to contract and recover. A potential deficiency can lead to muscle weakness or pain.

Mood changes or depression

Conditions such as anxiety or depression can be caused or worsened by vitamin D deficiency. Maintaining sufficient levels of this vitamin in adults can help reduce such symptoms as well as improve sleep quality or even prevent postpartum depression in pregnant women.

Frequent illness

Vitamin D is essential for the immune system and for fighting off infections and bacteria. If you often get colds or the flu, one of the reasons could be a vitamin D level that is too low. However, vitamin D supplements are not a substitute for medication or other methods of preventing infections.

Hair loss

Although scientific research on the topic is lacking, severe forms of hair loss could be the symptom of an illness related to vitamin D deficiency or nutrient deficiency.

What are the possible causes?

Limited sun exposure

The human body mainly gets the vitamin D it needs through the sun. People who rarely go outside, live far from the equator, or have jobs that limit their sun exposure are at a higher risk of vitamin D deficiency. In the winter months obtaining enough vitamin D through the sunlight can also get more difficult.

Age group

As we age, our skin gradually loses its ability to absorb enough vitamin D when exposed to the sunlight. People over the age of 65 are at risk of vitamin D deficiency and it is recommended to test their vitamin D level.

Inadequate intake of vitamin D through food

The main dietary sources of vitamin D include animal products such as fish (salmon, mackerel, sardines, herring) and fish oil, egg yolk and some types of fortified milk. The risk of deficiency is higher in people who do not consume enough of these products.

Dark skin

People with darker skin have more melanin. Melanin provides better protection against UV rays. This means that people with darker skin need to spend even more time in the sun to be able to obtain a sufficient amount of vitamin D.

Certain kidney problems

When 25-hydroxyvitamin D gets to the kidneys, it is converted into its final active form. As we age, and in some rare cases in people with kidney problems, the body loses its ability to convert the vitamin to its active form. This increases the risk of vitamin D deficiency.


Fat cells in the body are responsible for extracting vitamin D from the blood. This process could be disrupted in people who are overweight (especially in people with a BMI greater than 30).



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