What is Vitamin D and Why is it Important

Vitamin D is a fat-soluble vitamin that promotes calcium absorption in the gut and is needed in order for bones to grow properly. In its active form, it regulates calcium and phosphorus  metabolism, making it vital for bone formation. It also works with calcium to ensure that bones do not become thin or brittle. Because of this, it works well to prevent older adults from developing osteoporosis. 

Vitamin D has been shown to reduce inflammation in the body and assist the body in controlling infection by supporting proper function of the immune system.

Sufficient levels of vitamin D are important to prevent or combat infections, as studies have shown it may help in the prevention of, or be used as, a supportive treatment for many viral, bacterial, and fungal infections.

Some studies have shown that it has an important role in the respiratory tract, skin health, and gut health. A deficiency in vitamin D has been linked to some autoimmune diseases, like multiple sclerosis, Type I Diabetes, and rheumatoid arthritis. Studies have also shown that a deficiency in this very important vitamin has also been associated with various cancers and cardiovascular disease. 


What are Symptoms of a Vitamin D Deficiency

  • Frequent Illness

Since vitamin D supports the immune system, those who are frequently ill should consider checking on their vitamin D levels. Many studies have shown a link between respiratory tract infections such as colds, pneumonia, and bronchitis and low levels of vitamin D.


  • Muscle Pain or Weakness

The cause of muscle pain can be hard to determine at times. If it is non-specific muscle pain, vitamin D levels might be a factor. Some studies have associated musculoskeletal pain, headache, or fatigue with low levels of vitamin D. 

Another study showed 71% of those with chronic pain were deficient in the vitamin. 


  • Hair Loss

While there are various reasons for severe hair loss, one possible reason is a vitamin D deficiency. One study stated that those with low vitamin D levels and low serum ferritin levels were associated with hair loss. Low vitamin D levels have also been linked with alopecia areata, which is an autoimmune disease that causes severe hair loss. 


  • Depression

Depression may be another sign of a vitamin D deficiency. Some studies have shown a decrease in depression symptoms during the winter months when the participants supplemented with vitamin D. 


  • Poor Sleep Quality

The inability to get quality sleep can be a sign of vitamin D deficiency. One study determined that those with a vitamin D deficiency had a significantly increased risk of having some kind of sleep disorder. The study showed low vitamin D levels were associated with short sleep durations, sleepiness, and poor sleep quality.


  • Fatigue

Because feeling fatigued can be caused by many different things, a vitamin D deficiency might not be one of the first things you think to check. 

Studies have shown that low blood levels of vitamin D can cause enough fatigue to impact your quality of life.

One study done on women showed that those who had deficient or even insufficient blood levels of vitamin D were more likely to complain of fatigue and weakness.


  • Bone Pain

Knowing that it plays a vital role in bone production and health, it is no surprise that a deficiency in vitamin D could cause bone pain. The body needs vitamin D in order to keep bones strong, so without sufficient levels the bones are more likely to become brittle or fracture. 

What may be surprising is that studies have also found a link between low levels of vitamin D and chronic lower back pain. One study even associated a vitamin D deficiency with the severity of back pain and the inability to perform daily activities from that pain. 


  • Autoimmune Disease

There are several studies that suggest there may be a link between autoimmune diseases such as Multiple Sclerosis, Hashimoto’s Thyroiditis, Graves Disease, and Lupus. Studies have looked into the role a vitamin D deficiency plays in the severity of the disease, but also in the risk factor of developing the disease to begin with. 



Ways to Increase Your Vitamin D Levels

There are 3 main ways you can increase the amount of vitamin D you are receiving: exposing the skin to sunlight, through diet, or by supplementation.

The sun is the best and most readily available source of vitamin D. While there can be health concerns over getting too much sun exposure, the amount required to get an adequate amount of vitamin D should generally be no cause for concern. Receiving 10-30 minutes of midday sun exposure on the arms and legs, or the hands, arms, and face 2-3 times a week is a good goal to maintain adequate vitamin D levels. There are some factors that can reduce the skin’s production of vitamin D3 such as aging, increased skin pigmentation, applying sunscreen, and covering most of the body with clothing.

 It should also be noted that the further away you are from the equator, the more time it will require outdoors to receive adequate vitamin D because the sun’s UV rays are weaker in these locations.


Another option is to try increasing vitamin D levels through diet. The amount of foods that are vitamin D rich are very limited, but there are a few foods which naturally contain vitamin D. Cod liver oil is an excellent source of the vitamin. The flesh of fatty fish (salmon, tuna, mackerel) are other excellent sources. Foods such as beef liver, cheese, and egg yolks do contain smaller amounts as well. 


The final option would be to use a supplement. There are many vitamin D supplements on the market, but not all are created equal. The vitamin comes in two main forms:

  • Vitamin D2 (ergocalciferol)
  • Vitamin D3 (cholecalciferol)

Vitamin D2 comes mainly from plant or fortified sources, whereas vitamin D3 comes mainly from animal sources. The skin actually makes vitamin D3 when it is exposed to sunlight. 


Some studies have shown that vitamin D3 is more effective at raising blood levels of vitamin D when compared to vitamin D2. There are also other studies suggesting the quality of D2 supplements might not be as superior as D3 and might even deteriorate over time. 


One important note about supplementing with vitamin D pertains to those who have had their gallbladder removed. Since vitamin D is a fat-soluble vitamin, and the gallbladder stores bile, which is responsible for breaking down fats, those who have had their gallbladder removed will often find that the body’s ability to break down a vitamin D supplement is impaired. This can mean it will be difficult to raise vitamin D levels through typical supplementation. The best option in this instance would be to use a liposomal vitamin D supplement. 

At our office we carry two different vitamin D supplements, D-evail and Liposomal D. 



A review of the critical role of vitamin D in the functioning of the immune system and the clinical implications of vitamin D deficiency 

Vitamin D deficiency and fatigue: an unusual presentation 

Quality of life is impaired not only in vitamin D deficient but also in vitamin D-insufficient pre-menopausal women

Vitamin D status in patients with musculoskeletal pain, fatigue and headache: a cross-sectional descriptive study in a multi-ethnic general practice in Norway

Vitamin D and central hypersensitivity in patients with chronic pain  

Effects of vitamin D supplementation on symptoms of depression in overweight and obese subjects: randomized double blind trial

Vitamin D and depressive symptoms in women during the winter: a pilot study

Serum ferritin and vitamin d in female hair loss: do they play a role? 

Association between vitamin D levels and alopecia areata

Vitamin D deficiency in alopecia areata  

Vitamin D: modulator of the immune system 

The Association between Vitamin D Deficiency and Sleep Disorders: A Systematic Review and Meta-Analysis 

Association of back pain with hypovitaminosis D in postmenopausal women with low bone mass

Quality of life is impaired not only in vitamin D deficient but also in vitamin D-insufficient pre-menopausal women 

Vitamin D and Systemic Lupus Erythematosus: Myth or Reality?

The Role of Vitamin D in Thyroid Diseases

Low vitamin D status is associated with hypothyroid Hashimoto’s thyroiditis  

Vitamin D – Health Professional Fact Sheet

Sunlight and vitamin D for bone health and prevention of autoimmune diseases, cancers, and cardiovascular disease

Vitamin D: emerging roles in infection and immunity

Comparison of vitamin D2 and vitamin D3 supplementation in raising serum 25-hydroxyvitamin D status: a systematic review and meta-analysis 

“The case against ergocalciferol (vitamin D2) as a vitamin supplement.”