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8 signs and symptoms of a vitamin D deficiency

8 Anzeichen und Symptome für einen Vitamin D Mangel

Vitamin D is an extremely important vitamin that has powerful effects on multiple systems throughout the body (1). Unlike other vitamins, vitamin D functions like a hormone and every single cell in the body has a receptor for this vitamin.

The human body can produce vitamin D from cholesterol when the skin is exposed to the sun's rays. It is also found in certain foods such as oily fish and vitamin D-fortified dairy products, but it is very difficult to get sufficient amounts of vitamin D from food alone.

The recommended daily intake for vitamin D is in the range of 400 to 800 IU per day, but many experts say you should get more than that.

Vitamin D deficiency is very common. It is estimated that around one billion people worldwide have low levels of this vitamin in their blood (2). According to a study from 2011, around 41.6% of all US adults suffer from a vitamin D deficiency (3), although these values differ significantly among people of different ethnic backgrounds. For example, around 69.2% of all Hispanics and 82.1% of all African Americans suffer from a vitamin D deficiency (3).

Here are 7 risk factors for vitamin D deficiency:

  • A darker skin tone
  • Older age
  • Being overweight or obese
  • Low consumption of fish or dairy products
  • Living far from the equator where there is little sun all year round
  • Regular use of sunscreen
  • Leaving the house too rarely and spending most of your life indoors

People who live near the equator and are regularly exposed to the sun have a much lower risk of vitamin D deficiency, as their skin produces enough vitamin D when exposed to sunlight to meet the body's needs.

Most people do not realize that they have a vitamin D deficiency as the symptoms are usually subtle. They are not easy to recognize, even if they have a significant negative impact on quality of life.

Here are 8 signs and symptoms of vitamin D deficiency:

1. frequent infections and illnesses

One of the most important roles of vitamin D is to keep the immune system strong so that the body is able to fight viruses and bacteria that cause disease. Vitamin D interacts directly with the cells that are responsible for fighting infections (4).

If you get sick often - which is especially true for infectious diseases like colds and flu - low vitamin D levels could be a contributing factor. Several observational studies have shown a link between vitamin D deficiency and respiratory infections such as the common cold, bronchitis and pneumonia (5, 6).

A number of studies have found that taking a vitamin D supplement at doses of up to 4,000 IU per day can reduce the risk of respiratory infections (7, 8, 9).

In a study of patients suffering from chronic obstructive pulmonary disease (COPD), only those who were severely vitamin D deficient experienced significant benefits after taking a high-dose vitamin D supplement for one year (10).

Summary: Vitamin D plays important roles in immune function. One of the most common symptoms of a deficiency is an increased risk of illness or infection.

2. tiredness and fatigue

Feeling tired can have many causes and a vitamin D deficiency could be one of them. Unfortunately, such a deficiency is often overlooked as a cause of persistent fatigue. Case studies have shown that very low blood levels of vitamin D can cause fatigue, which has serious negative effects on quality of life (11, 12). In one case, a woman complaining of chronic fatigue during the day and headaches was found to have a vitamin D blood level of only 5.9 ng/ml. This is very low, as anything below 20 ng/ml is considered a deficiency. After this woman took a vitamin D supplement, her vitamin D blood levels rose to 39 ng/ml and her symptoms disappeared (12).

However, even blood levels that are not extremely low can have negative effects on energy levels. A large observational study examined the relationship between vitamin D and fatigue in young women. The study found that women with blood levels below 20ng/ml or with blood levels between 21 and 29 ng/ml were more likely to complain of fatigue than women with blood levels above 30ng/ml (13).

Another observational study using female nurses as subjects found a strong association between low vitamin D levels and fatigue. This study also found that 89% of nurses were vitamin D deficient (14).

. Summary: Excessive tiredness and fatigue could be a sign of vitamin D deficiency. Taking supplements can help to boost energy levels in this case.

3. bone and back pain

Vitamin D helps to maintain bone health in several ways. Among other things, it improves the absorption of calcium in the body. Bone pain and lower back pain may be signs of inadequate vitamin D blood levels.

Large observational studies have found a link between vitamin D deficiency and chronic low back pain (15, 16, 17). One study examined the association between vitamin D levels and back pain in over 9,000 older women. The researchers found that the women with vitamin D deficiency were more likely to suffer from back pain, including serious back pain that interfered with their daily activities (17).

In a controlled study, people with vitamin D deficiency were twice as likely to suffer from bone pain in their legs, ribs or joints as people with normal vitamin D blood levels (18).

Summary: Low vitamin D levels may be the cause or a contributing factor in bone pain and back pain.

4 Depression

Depressed mood can also be a sign of vitamin D deficiency. In review studies, researchers have linked vitamin D deficiency - particularly in older adults - to depression (19, 20). In one analysis, 65% of observational studies found a relationship between low vitamin D levels and depression.

On the other hand, most controlled studies, which carry more scientific weight than observational studies, showed no association between vitamin D deficiency and depression (19). However, the researchers who examined these studies noted that the vitamin D doses used in controlled trials were often very low. In addition, they observed that some of the studies may not have lasted long enough to observe an effect of taking a vitamin D supplement on mood.

Some controlled studies have shown that giving vitamin D to people who are deficient can alleviate depression, including so-called winter depression, which occurs during the colder months of the year (21, 22).

Summary: Depression is associated with low vitamin D levels and some studies have found that vitamin D supplementation can improve mood.

5 Impaired wound healing

Slow healing wounds after surgery or injury can be a sign that your vitamin D levels are too low. Results from a test tube study suggest that vitamin D increases the production of compounds that are crucial for skin regeneration as part of the wound healing process (23).

A study of subjects who had undergone dental surgery found that certain aspects of the healing process were impaired by vitamin D deficiency (24).

It has also been suggested that the role vitamin D plays in controlling inflammation and fighting infection is important for proper wound healing. A study involving patients with diabetic foot infections found that subjects who were severely vitamin D deficient were more likely to have higher levels of inflammatory markers that can impede wound healing (25).

Unfortunately, there is very little research on the effects of vitamin D supplements on the wound healing process in people suffering from vitamin D deficiency. However, one study found that in patients with leg ulcers who were vitamin D deficient and treated with vitamin D, the size of the ulcers decreased by an average of 28% (26)

Summary: Inadequate vitamin D levels can lead to poor wound healing.

6 Bone resorption

Vitamin D plays a crucial role in calcium absorption and bone metabolism. Many older people who have been diagnosed with bone loss believe that they need to take more calcium. However, they may also suffer from a vitamin D deficiency.

Low bone mineral density is an indicator that the bones have lost calcium and other minerals. This results in an increased risk of fractures in older adults - and especially older women.

A large observational study of more than 1,100 middle-aged women who were menopausal or past menopause found a strong association between low vitamin D levels and low bone mineral density (27).

However, a controlled study found that women who were vitamin D deficient did not experience an improvement in bone mineral density when taking high-dose vitamin D supplements, even when vitamin D blood levels improved (28).

Regardless of these results, adequate vitamin D intake and maintenance of normal vitamin D blood levels may be a good strategy to protect bone mass and reduce the risk of fractures.

Summary: Low bone mineral density could be a sign of vitamin D deficiency. Adequate vitamin D intake is important for maintaining bone mass as we age.

7. hair loss

Hair loss is often attributed to stress, which is certainly a common cause. However, if hair loss is severe, it could also be the result of a nutritional deficiency.

Hair loss in women has been linked to low vitamin D levels, although there is still very little research on this topic (29).

Alopecia Areata is an autoimmune disorder characterized by severe hair loss on the head and other areas of the body. This condition is associated with rickets - a disease that causes soft bones in children due to vitamin D deficiency (30).

Low vitamin D levels are associated with alopecia areata and may be a risk factor for the development of this disease (31, 32, 33). A study of subjects suffering from alopecia areata showed that lower blood levels of vitamin D tended to be associated with greater hair loss (33).

In a case study, it was found that the application of a synthetic form of vitamin D to the skin successfully treated hair loss in a young boy who had a defect in the vitamin D receptor (34)

Summary: Hair loss could be a sign of vitamin D deficiency in female pattern hair loss or the autoimmune disease alopecia areata.

8 Muscle pain

The causes of muscle pain are often difficult to pin down. There is evidence that vitamin D deficiency could be a potential cause of muscle pain in children and adults (35, 36, 37). One study found that 71% of people suffering from chronic muscle pain were vitamin D deficient (37).

The vitamin D receptor is also found in nerve cells known as nociceptors, which perceive pain. A study conducted in rats showed that vitamin D deficiency led to pain and tenderness due to stimulation of nociceptors in the muscles (38).

A few studies have found that taking a high-dose vitamin D supplement can reduce different types of pain in people suffering from vitamin D deficiency (39, 40). A study of 120 children suffering from growing pains and vitamin D deficiency found that a single dose of vitamin D could reduce pain levels by an average of 57% (40).

Summary: There is a link between chronic pain and low blood levels of vitamin D, which could be due to an interaction between vitamin D and the nerve cells that perceive pain.


Vitamin D deficiency is very common and most people are not aware of this deficiency. This is because the symptoms are often subtle and non-specific, which means that it is difficult to know whether they are caused by a vitamin D deficiency or something else.

If you suspect you are suffering from a vitamin D deficiency, it is important that you speak to your doctor and have your blood levels of this vitamin tested.

Fortunately, a vitamin D deficiency is usually easy to compensate for. You can do this by spending more time in the sun and eating more vitamin D-rich foods such as oily fish and vitamin D-fortified foods. There are also a variety of vitamin D supplements available on the market.

Compensating for a vitamin D deficiency is easy and can have great benefits for your health.




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