Vitamin D: Understanding deficiency

Vitamin D is often called the sunshine vitamin because we obtain it through exposure to ultraviolet B radiation in sunlight. But since there is no required ultraviolet B radiation in fall and winter, our bodies cannot produce enough of it, if at all.  

Vitamin D deficiency can also develop for the following reasons: 

  • There’s not enough exposure to sunlight all year round or too much sun screen is used 
  • There’s not enough of this vitamin in your diet
  • You have a malabsorption problem
  • There are certain health disorders, such as kidney, liver or hereditary diseases, that impair vitamin D conversion into active metabolites

The importance of vitamin D lies in the fact that it plays a role in regulating the absorption of phosphorus and calcium, as well as in promoting normal immune system functioning. Getting enough of this vitamin is essential for development of bones and teeth, and enhanced resistance to certain illnesses. It is also essential for muscle and nervous system. 

Vitamin D actually becomes a secosteroid hormone in the body. It has a huge impact not only on the skeletal structure, but also on immunity, blood pressure, brain function, mood and the ability to protect ourselves from cancer. 

When we are low on vitamin D, the bone mineralization becomes impaired, resulting in bone softening diseases, such as rickets in children, and osteoporosis and osteomalacia in adults.  Another common effect is muscle aches and weakness, which further increases the risk for fall and bone fractures. Other problems resulting from the lack of this vitamin include: 

  • Infections. One of important roles of vitamin D is to keep the immune system strong so as to fight viruses and bacteria. Thus, its deficiency can easily cause respiratory conditions like cold, flu, bronchitis and pneumonia. 
  • Muscle twitching. Reduced ionised calcium that arises from vitamin D insufficiency often causes muscular cramps or twitching. 
  • Periodontitis. Lack of vitamin D may cause local soft tissue inflammation that over time causes bone loss and eventually leads to tooth fallout.  
  • Depression. Vitamin D protects against the depletion of hormones that affect mood, and namely dopamine and serotonin. 
  • Pre-eclampsia. Besides its association with developing pre-eclampsia, vitamin D deficiency in pregnant and breastfeeding women may also cause an overt bone disease in babies before and after birth.  

Researchers also associate this vitamin with diabetes, metabolic syndrome, common cancers, multiple sclerosis and hypertension.    

Certain people are more at risk to be low on vitamin D: 

  • Elderly. As we age, our skin synthesizes vitamin D from sunlight less efficiently. 
  • Dark-skinned. People with dark skin have higher melanin levels, which reduces the amount of vitamin D production.  
  • Obese. The body fat in people with obesity binds to some vitamin D and prevents it from getting into the blood.
  • Chronically ill. Since vitamin D is fat soluble, people with celiac or Crohn’s disease who don’t handle fat properly become affected.

Fortunately, there are ways to increase vitamin D levels naturally and minimize the risk for developing health issues. The surest way is to spend more time outdoors, without sunscreen. You can also get vitamin D eating certain foods, such as beef liver, mushrooms, egg yolks, fortified dairy products and fatty fish as tuna, salmon or mackerel, though it’s not enough from diet alone. Then you can treat deficiency with multivitamins which contain vitamin D or receive vitamin D supplements. However, the latter must be prescribed by the doctor, as supplements overuse can cause toxicity, whereas excessive exposure to sun light doesn’t induce vitamin poisoning as the body naturally limits the amount it produces.