Vitamin D Deficiency, Causes, Symptoms and Treatment

What is Vitamin D?

Vitamin D is an organic substance with a steroid structure, which differs from other vitamins in that it can be synthesized in our body and is even considered a pro-hormone. The main source of 80-90 percent is the sun (UV rays), and 10-20 percent is some foods. Internal Medicine Specialist Dr. Özlem Durmuş ARIN states that the production steps initiated by UV rays in our skin end with the production of active vitamin D in the liver and kidney. Dr. ARIN explained the little-known benefits of this vitamin, the reasons for its decrease in the body, and the problems that may occur in its deficiency as follows:

What are the Functions of Vitamin D?

While vitamin D affects hundreds of genes involved in repair and maintenance in the body, it is also a biological regulator. Without vitamin D, even if kilos of calcium enter the body orally, the body cannot use it adequately and cannot absorb it from the intestine. Calcium and phosphorus absorption is essential for bone health. In addition to skeletal health, it also has important functions that support the immune system, skin-hair-nail health, digestion, circulation and nervous system. For these reasons, appropriate vitamin D levels are also important in the fight against many chronic diseases such as depression, diabetes, cancer and cardiovascular diseases. Low vitamin D levels may lead to the development of diabetes by increasing insulin resistance and worsening pancreatic beta-cell function.

What Causes Vitamin D Deficiency?

Conditions that cause vitamin D deficiency can be listed as follows: 

• Insufficient sun exposure (Reasons such as staying in closed areas for a long time and increasing air pollution prevent the sun's rays from reaching our skin.) ¦ 
• Old age (Vitamin D production decreases in people over the age of 70 because their kidney-liver functions decrease and/or chronic diseases affecting them are common. Another reason is that they spend more time in closed environments.) ¦ 
• Dark skin (Dark skinned people need to be exposed to the sun for longer because the melatonin pigment, which gives the skin its color, absorbs UV rays and prevents them from reaching the skin.) ¦ 
• Medicines (Epilepsy, tuberculosis drugs, long-term use of cortisone cause the breakdown of vitamin D.) 
• Obesity (They cannot benefit from the beneficial rays of the sun because they generally prefer closed clothing and lead a sedentary life.) 
• Insufficient consumption of milk, dairy products and fish 
• Gastrointestinal malabsorption diseases 
• Chronic kidney and liver diseases (These diseases can disrupt vitamin D production stages.) 
• Parathyroid diseases

How High Should Vitamin D Levels Be?

<10 ng/ml ("ug/l) severe deficiency 
10-20 ng/ml moderate deficiency 20-30 ng/ml mild deficiency 
 30-50 ng/ml desired level 
 >100 ng/ml increased risk of poisoning 
 > 150 ng/ml vitamin D poisoning

How to Keep Vitamin D in Balance?

According to the 25 hydroxy vitamin D level measured in the blood, in order to keep our vitamin D level >30 ng/ml, a minimum of 600-2000 iu and a maximum of 4000 iu of vitamin D should be used daily. The geographical region, existing diseases, medications used, age and gender affect the dose to be used. In severe deficiencies, loading doses are used. Higher doses should be used for longer periods of time for people in risk groups. It should be given with additional vitamin K2 in those who cannot consume animal and/or fermented foods and in diseases that negatively affect the intestinal microbiome, such as chronic inflammatory bowel disease. In summary, the goal is to keep our vitamin D level above 30 ng/ml. For this, we just need to pay attention to a few things. The simplest and most accessible way for our country is to be exposed to the sun at least 2-3 days a week, between May and November, between 10:00 and 15:00. While this duration should be 15-20 minutes for someone with light skin, it should be at least 20-30 minutes for someone with dark skin. If there is a face-neck-back-of-hand area of the body, scars/surgery scars should be protected with sunscreen and more than half of the body should be exposed to the sun. Glass or curtains do not provide any benefit as they block UV rays. The second way is to frequently consume a small number of foods containing vitamin D, but the daily requirement cannot be met with foods alone. These can be fatty fish such as salmon, tuna, mackerel, sardines, egg yolks, butter, milk, cheese, sweet potatoes, parsley, red meat and liver. A calcium-rich diet also allows vitamin D to do its job. If this vitamin is deficient or insufficient despite these measures, supplements (drops/capsules) should be used with the recommendation of a doctor.

Vitamin D in the World and Our Country

Vitamin D deficiency affects 13 percent of the population worldwide. In our country, although we are geographically lucky in terms of sunlight, vitamin D deficiency has been detected at a rate of up to 60 percent. 
The rate increases in the north-east, where winter lasts longer. Reasons such as insufficient sun exposure, air pollution, dark skin, closed clothing, relatively low consumption of fish and dairy products, and inadequate follow-up and treatment are blamed for this. When celiac disease, chronic inflammatory bowel diseases, liver-kidney diseases, and some medications (epilepsy, tuberculosis, steroid drugs) are added to these, the rate increases even more. 
This is reflected in the form of bone mineral decrease (osteopenia, osteomalacia), osteoporosis and bone fractures. The worse part is that these conditions do not cause symptoms until they occur. However, if there is a long-term and serious low vitamin D level, such as years, bone pain and tenderness may be felt. Apart from that, weakness, fatigue and weakness, which can be seen in every disease, are the main symptoms. Unfortunately, we cannot be aware of these until we have a bone measurement or experience a bone fracture.