Vitamin D Deficiency: Causes, Common Symptoms and Treatment

In the UAE, vitamin D deficiency is very common despite the year round sunshine. One reason for this is that we prefer to cover up, stay out of the sun and wear high factor sunscreen.

What is Vitamin D? How do we know if we are getting enough of it? How can we improve our Vitamin D levels? Dr Ruhil answers all of our questions around Vitamin D and the importance of it.


Vitamin D is also known as the ‘Sunshine Vitamin’. It is a vitamin that has several important functions in the body:

  • Maintains the health of bones and teeth.
  • Supports the immune system, brain and nervous system.
  • Important for diabetes management as it can regulate insulin levels.
  • Helps with lung function and cardiovascular health.
  • May help protect against cancer cell development.

Through these actions, we can see that vitamin D has many important benefits. It may have other benefits, such as improving muscle and immune function, but these areas require more research.


Sources of Vitamin D

Vitamin D is made in the skin under the influence of sunlight. The amount of sunlight needed to synthesize adequate amounts of vitamin D varies, depending upon the person’s age, skin color, sun exposure, and underlying medical problems. Estimates of mild direct sun exposure to bare skin is about 5-10 minutes, 2-3 times per week. The production of vitamin D from the skin decreases with age. In addition, people who have darker skin need more sun exposure to produce adequate amounts of vitamin D, especially during the winter months.

We can also source vitamin D from various foods such as fatty fish, cod liver oil, eggs and chicken, where it is found naturally. We can also purchase cow’s milk, cereals and bread products commercially fortified with Vitamin D.


What causes Vitamin D deficiency?

Under most circumstances, Vitamin D deficiency is caused by the following reasons:

1 – Lack of vitamin D in the diet, often in conjunction with inadequate sun exposure

Babies, children and older adults are at a higher risk of low vitamin D levels due to their diet. Both human breast milk and infant formula contain very low levels of Vitamin D, therefore very young babies must be supplemented with Vitamin D drops. The elderly may also not consume enough Vitamin D rich foods, and if they do, the absorption in the body is limited.

New parents are also usually advised to keep young babies away from direct sunlight, which reduced Vitamin D synthesis from the skin. Older Adults tend to also shy away from the sun, as they may not be as mobile or active. The risk is higher for those with darker skin tones, and as we age, our skin naturally reduces the amount of Vitamin D made in the skin. Applying sunscreen also limits Vitamin D synthesis from the sun.

2 – Inability to absorb vitamin D from the intestines

Diseases like Celiac Disease, Crohn’s Disease and Cystic Fibrosis effect the body’s ability to absorb the right amount of Vitamin D through the intestines. If you have had surgery such as Gastric Bypass, you are also at higher risk of vitamin D deficiency.

3 – Inability to process vitamin D due to kidney or liver disease

The liver and kidney have important enzymes that change vitamin D from sun-exposed skin or food to the biologically active form of vitamin D. People with chronic kidney and liver disease are at increased risk of low active vitamin D levels because they have decreased levels of these enzymes.


Symptoms of Vitamin D Deficiency

The symptoms associated with vitamin D deficiency could include:

  • Fatigue
  • Painful back, or pain in bones
  • Depression
  • Hair Loss
  • Muscle Pain
  • Catching a cold or virus often
  • Slower wound healing


Diagnosis of Vitamin D Deficiency

Vitamin D deficiency can be easily checked through a simple blood test called the 25-hydroxy Vitamin D blood test. Usually, results showing a level of 20 nanograms/millilitre to 50 ng/mL is considered adequate.

Some patients may be diagnosed with vitamin D deficiency or vitamin D insufficiency. It is very common and is defined as a lower than normal vitamin D level that has no visible signs or symptoms


Treatment for Vitamin D Deficiency

There are many types of vitamin D supplements available for the treatment of vitamin D deficiency or insufficiency. The two commonly available forms of vitamin D supplements are vitamin D2 or vitamin D3. We suggest vitamin D3 when possible, rather than vitamin D2, because vitamin D3 is the naturally occurring form of the vitamin and it may raise vitamin D levels more effectively. Your doctor will recommend what is best for you based on your test results.



As mentioned previously, the amount of vitamin D you need per day to maintain a normal level depends upon your skin color, sun exposure, diet, and underlying medical conditions.

In general, adults are advised to take a supplement containing 800 international units (20 micrograms) of vitamin D per day to maintain a normal vitamin D level. Older people who are confined indoors may have vitamin D deficiency even at this intake level.

All infants and children are advised to take a vitamin D supplement containing 400 international units (10 micrograms) of vitamin D, starting within days of birth. For infants and children, vitamin D is included in most nonprescription infant multivitamin drops. In some countries, it is possible to buy infant drops that contain only vitamin D.

Lengthy exposure to the sun or tanning beds is not recommended as a source of vitamin D, because of the risk of skin cancer.

Dr Ruhil Badiani

Family Medicine Consultant
Medical Director

If you have any questions or concerns about your health, especially Vitamin D. Ask your Health at Hand doctor for advice through our app that can be easily downloaded from the App Store. Click here for more information.