Symptoms of Vitamin D Deficiency


Vitamin D is typically related to sun exposure, bone health, and immune health; however, vitamin D is different than every other vitamin: vitamin D functions like a hormone and every cell in the human body has a receptor for vitamin D. The human body makes vitamin D when skin is exposed to sunlight, through converting cholesterol into the vitamin. People can also acquire vitamin D through their diet by eating fatty fish and fortified dairy products, but it is challenging to get proper amounts through diet alone.

This article will be all about vitamin D, precisely the symptoms of vitamin D deficiency.

Fatigue and Tiredness

Though feeling tired can be due to a wide array of causes, insufficient vitamin D consumption is often one of them.

In a 2015 study, researchers noted measuring vitamin D levels is not a common approach to treating patients with fatigue, so they set to investigate the relationship. The researchers found after conducting several tests on a patient with severe fatigue and finding no abnormalities, they did a vitamin D test and found the vitamin’s levels were low. They administered a vitamin D routine, and at the three- and twelve-month follow-ups, the patient noted he was no longer fatigued. The researchers hypothesized this resulted from vitamin D’s role in inflammatory cascades, which result in decreased central nervous system homeostatic sleep pressure [1].

In a 2010 case, a woman had hypersomnia. For four months, she had excessive daytime sleepiness, chronic pain in the lower back and thighs, and chronic headaches. The researchers found her vitamin D levels were low and administered 50,000 IUs of vitamin D once a week. After a few weeks, her sleep problems were resolved, and her headaches, back, and thigh pain went away. Again, the researchers hypothesized this was because of vitamin D’s role with the inflammatory system [2].

In a more extensive, 2013 study, researchers examined the relationship between vitamin D levels and fatigue in young women. The researchers found women with low and deficient vitamin D levels were more likely to complain about fatigue than women who had higher levels of vitamin D [3]. Thus, higher vitamin D levels resulted in a more exceptional quality of life.

In a 2015 study, researchers investigated the relationship between vitamin D levels in female nurses and fatigue. There were 200 nurses in the study, and they were given a survey containing nine questions, each with a 1-to-7, Likert-type scale. Therefore, each nurse could have a score between 9 and 63. Then, the nurses had their vitamin D levels tested. The researchers found a correlation between low vitamin D levels and fatigue and concluded, “High prevalence of fatigue among nurses could be attributed to vitamin D ‎deficiency” [4].

To summarize, because of vitamin D’s effect on inflammation and the nervous system, there could be a relationship between low vitamin D levels and fatigue.

Bone and Back Pain

Vitamin D can help to maintain bone health because it helps to improve the body’s absorption of calcium. Therefore, lower vitamin D levels may be a cause of bone and lower back pain.

Three, extensive studies – 328 patients, 994 patients, 9,305 patients – found a relationship between a vitamin D deficiency and lower back pain [5] [6] [7].  

In the largest of the three studies, researchers found those with a deficiency were much more likely to have lower back pain, to the point where the pain would limit their daily activities [7].

In 2010, researchers conducted a controlled study, investigating the association between vitamin D levels and nonspecific skeletal pain, pain in the leg, widespread pain, rib pain, back pain, and fibromyalgia. The researchers concluded, “The results of this study indicate a positive association of vitamin D deficiency with a variety of nonspecific bone pain, particularly in women” [8].

To summarize, the is a relationship between the prevalence of bone pain and decreased levels of vitamin D.

Slower Wound Healing

I am aware this is an oddly specific symptom, but it is an interesting symptom, nonetheless.

If someone had surgery followed by an abnormally lengthy healing process, it could be because they have low levels of vitamin D. This is mainly because vitamin D plays a vital part in the formation of new skin in the wound-healing process [9].

In a 2011 study, researchers investigated the relationship between a patient’s recovery time after periodontal surgery and vitamin D levels. The researchers found certain aspects of the recovery were impaired due to low vitamin D levels [10].

A 2014 study examined vitamin D levels in patients with foot infections caused by diabetes. The researchers discovered individuals with severe vitamin D deficiencies were more likely to have higher levels of inflammatory markers which threatened the healing process [11].

In a 2012 study, researchers analyzed the relationship between vitamin D insufficiency and wound healing in patients with venous ulcers in their legs. The researchers found those who were given vitamin D had a reduction in their ulcer size by an average of 28% [12].

To summarize, while the research may still be young, there seems to be a correlation between low vitamin D levels and poorer wound healing.

Perpetual Sickness

Though this may be a given because vitamin D’s role in immune system function is generally known, it is still essential to examine.

Vitamin D directly interacts with cells which fight infections in the human body, as a 2011 study found [13]. The study also found infections such as “tuberculosis, psoriasis, eczema, Crohn's disease, chest infections, wound infections, influenza, urinary tract infections, eye infections, and wound healing” may benefit from lower vitamin D levels, meaning lower levels would make these infections stronger [13].

There are also a fair amount of studies investigating the relationship between respiratory infections and vitamin D levels.

A 2017 review of 2,279 patients found there was a relationship between vitamin D levels and the incidence and severity of lower respiratory tract infections [14].

A 2014 study examined the relationship between vitamin D levels and the severity of pneumonia in 300 randomly selected patients. The researchers found a significant and independent negative correlation between 1,25-OH2 (active-form vitamin D3) and pneumonia severity [15].

Further, a 2013 study found vitamin D to show a protective effect against respiratory tract infections (RTI) [16], a 2010 study found vitamin D3 supplementation during the winter may reduce the chance of the flu in schoolchildren [17], and a 2015 study vitamin D supplementation to significantly decrease the likelihood of acquiring an RTI during the study period [18].

To summarize, there are a plethora of studies linking vitamin D levels to chances of acquiring sickness.

Mood and Depression

While the research may be lacking, several studies have linked decreased vitamin D level and depression.

A 2016 study investigating the potential mood benefits of vitamin D supplementation found the vitamin did play a role in depression [19], and a 2014 meta-analysis found an inverse association between D3 levels and the risk of depression [20].

A 2008 study, again, found a relationship between D3 levels and symptoms of depression [21].

In 2009, researchers took a unique approach to depression and vitamin D supplementation. They hypothesized vitamin D supplementation might decrease depressive symptoms during the winter months, and they concluded, “This study suggests that supplemental vitamin D3 reduces depressive symptoms” [22].

To summarize, while there may not be a lot of research, the relationship between low vitamin D levels and increased chances of depression seems likely.

Muscle Pain

While the term muscle pain is very, very generic, some studies have found that a vitamin D deficiency may be the potential culprit [23] [24] [25].

In one of the studies, researchers investigated vitamin D deficiency in 174 patients and found 74% of them to be deficient in the vitamin [25]. The researchers noted this could be because decreased vitamin D levels result in increased central pain sensitivity, like the point made earlier with vitamin D’s role with bone and back pain [25]. Remember, vitamin D receptors are in every cell in the human body, including those that sense pain.

A 2012, randomized, controlled trial studied the effect of high-dose vitamin D3 on nonspecific persistent musculoskeletal pain. The patients were either given a placebo or a 150,000 IU dose of vitamin D3. After six weeks, patients who received the D3 reported a positive effect [26].

When children grow, they often experience growing pains. In a 2015 study, researchers found, “In the 120 patients with growing pains, vitamin D insufficiency was noted in 104 (86.6%).” In that study, the researchers concluded, “supplementation with oral vitamin D resulted in a significant reduction in pain intensity among these children with growing pains” who were vitamin D3 deficient [27].

To summarize, research shows there is a link between low vitamin D levels and muscle pain and vitamin D supplementation may help to reduce such pain.

Hair Loss

While there may be straightforward causes of hair loss such as stress or chemotherapy treatment, deficiencies in specific nutrients may also contribute, with vitamin D being one of them.

One 2013 study showed a direct relationship between decreased vitamin D2 levels and hair loss in females [28].

However, there seems to be a more significant relationship between vitamin D levels and the chances of alopecia areata (AA), an autoimmune disease characterized by severe hair loss [29] [30] [31] [32].

In fact, a 2014 study showed low D3 levels are present in patients with AA and are inversely related to the disease’s severity [32].


To summarize this article, decreased levels of vitamin D are associated with, sometimes forcefully, various diseases and ailments, including tiredness and fatigue, bone, back, and muscle pain, slow wound healing and perpetual sickness, hair loss, and decreased mood.

If you are concerned about your vitamin D levels, your doctor can conduct tests to determine your levels.

Also, if you are looking for a vitamin D supplement, Healthmasters’ Ultimate D3-10,000 with K2 is an excellent vitamin D3 supplement.

If you have any questions about Healthmasters’ Ultimate D3-10,000 with K2, please feel free to call us at 800.726.1834.