By Dr. Bilal Shirazi | 18 Sep 2018

Vitamin D deficiency - the unknown global health problem

Vitamin D deficiency is one of the most common medical conditions worldwide. Our latest blog sheds light on this growing but widely unknown health issue, including the key warning signs and how to prevent it.


Vitamin D deficiency is one of the most common medical conditions worldwide. An estimated 1 billion people suffer from serious vitamin D deficiency, while up to half of the global population do not have adequate levels of vitamin D.

Our latest blog sheds light on this growing but widely unknown health issue, including the key warning signs and what you can do to prevent it. 

  1.        Why is vitamin D important?

Vitamin D is important as it helps our bodies absorb calcium which is vital for bone and muscle health.  A lack of vitamin D can lead to bone conditions such as rickets in children and osteomalacia in adults.

Recent studies also suggest that vitamin D could help to lower your risk of developing certain diseases such as cancer and type II diabetes. 

  1.        Where do I get vitamin D from?

Our main source of vitamin D comes from the sun which is why it is also known as the "˜sunshine vitamin'. Our bodies produce vitamin D when our skin is exposed to sunlight.

  1.        Who is most prone to vitamin D deficiency?

Certain groups are at greater risk of vitamin D deficiency. These include:

  • People that get less exposure to sunlight, such as those living at a high latitude or in highly polluted areas, or that spend little time outdoors.
  • People with darker skin as they need more sunlight exposure to absorb enough vitamin D.
  • Pregnant women and breastfeeding women because the nutritional demands of their baby may lower vitamin D levels in their body.
  • Likewise breastfed babies have a higher risk of vitamin D deficiency (This does not apply to babies on formula as this is usually fortified with vitamin D).
  • People with other health factors that impact their ability to absorb vitamin D, including gut problems or being overweight. 

Surprisingly Vitamin D deficiency is highly prevalent in parts of the world that get a lot of sunshine, including Asia, Africa and the Middle East. This may be a result of the very hot climate which prevents people from spending much time outside or because of cultural practices which mean the skin is often covered. 

  1.        What are the symptoms of vitamin D deficiency?

Many people with vitamin D deficiency are unaware of their condition. This is because the symptoms are often subtle and non-specific. They include:

  • Fatigue and tiredness
  • Depression or changes in mood
  • Bone and/ or muscle pain
  • Brittle bones or fractures
  • Low immune system, e.g. frequent colds
  • Decreased athletic performance or endurance
  1.        How can I prevent vitamin D deficiency?

Sunlight: The best way to boost your vitamin D levels is by increasing the exposure of your skin to sunlight. Ideally you should aim to spend 15-20 minutes per day in natural sunlight. Yes you heard it here first - you now have a legitimate excuse to book that beach holiday!

Diet: You can also get more vitamin D by eating foods that naturally contain this vitamin. These include egg yolks, fatty fish such as salmon, tuna and mackerel, beef liver, mushrooms and fortified foods (e.g. some cereals and dairy products). 

Get tested: If you think you may have a vitamin D deficiency or be at higher risk, then you should ask your doctor about getting your blood levels measured. Vitamin D deficiency is defined as having less than 30 nmol/L in a serum concentration of 25(OH)D. Many people may have low levels of vitamin D from time to time (sometimes called vitamin D insufficiency) but not a medical deficiency.    

Supplements: Those with serious vitamin D deficiencies can consider taking supplements. However it's important not to overdo it, as taking excessive amounts of vitamin D can cause a build up of calcium in the body and lead to other health problems. It's also important to check whether your health insurance covers you for vitamin D supplements. International health plans only cover costs for those with a genuine vitamin D deficiency, not for vitamin D insufficiency as this is extremely common.