What are the main causes of vitamin D deficiency?

The study of vitamin D it is now included in many preventive packages. Sometimes the results show that its levels are lower than the recommended range. In this article, we'll look at the main causes of low levels and why it's important to take action. 

Which vitamin D3 levels are too low?

Levels of 50 nmol/L (20 ng/mL) or higher are sufficient for most people for bone health and overall health. Levels below 30 nmol/L (12 ng/mL) are too low and can weaken your bones and affect your health. A range between 12 ng/mL and 20 ng/mL is considered a mild to moderate deficiency. Levels above 125 nmol/L (50 ng/mL) are too high and can cause health problems.

Vitamin D deficiency has symptoms right when you wake up

Vitamin D deficiency diseases

Vitamin D is one of the many vitamins that the body needs for good health. It plays a crucial role in maintaining the balance of calcium in the blood and bones and in building and maintaining bones.

A person needs vitamin D to properly absorb calcium and phosphorus in the bones and to maintain healthy tissues.

In chronic and/or severe vitamin D deficiency, decreased absorption of calcium and phosphorus in the gut leads to hypocalcemia (low calcium levels in the blood). This, in turn, can cause secondary hyperparathyroidism – overactive parathyroid glands trying to maintain normal levels of calcium in the blood. 

Both hypocalcemia and hyperparathyroidism, if severe, can cause symptoms including muscle weakness and cramps, fatigue, and depression.

Vitamin D - how to get it and when there is a deficiency

The body tries to balance calcium levels in the blood through secondary hyperparathyroidism and by taking calcium from your bones. This leads to accelerated bone demineralization. It means that the bone is being broken down faster than it can be built up. It can further lead to osteomalacia (soft bones) in adults and rickets in children.

Osteomalacia and osteoporosis create an increased risk of bone fractures. Rickets is the same as osteomalacia, but only affects children. As the child's bones are still growing, demineralization causes curved or bent bones.

Absorption of vitamin D - why a deficiency occurs

The main causes of vitamin D deficiency are due to several main reasons:

• Not enough sun exposure: Vitamin D is mainly synthesized in the body when your skin is exposed to sunlight. Limited exposure to sunlight, especially in regions with low sunlight intensity, can lead to a deficiency. It occurs if a person spends most of their time indoors, wears clothing that covers most of the skin, or uses excessive sunscreen. It is also found in areas with long winters.
• Darker skin pigmentation: Melanin, the pigment responsible for skin color, acts as a natural sunscreen and reduces the skin's ability to produce vitamin D. People with darker skin need longer exposure to the sun to produce adequate amounts of vitamin D compared to those with lighter skin.
• As they age, their skin becomes less efficient at producing vitamin D when exposed to sunlight. Older adults may also spend more time indoors, further reducing their sun exposure.
• Although it is possible to get vitamin D from food sources such as fatty fish, fortified dairy products and egg yolks, these sources may not provide sufficient amounts of the vitamin for many people. Vegans and people with certain dietary restrictions may be at higher risk of deficiency if they do not consume fortified foods or take vitamin D supplements.
• Obesity is another possible cause. Vitamin D is fat-soluble, and excess body fat can absorb and retain vitamin D, making it less available to the rest of the body. This can lead to lower circulating levels of vitamin D, even if sun exposure and dietary intake are adequate.
• Absorption disorders: This cause of vitamin D deficiency occurs with medical conditions that affect the gastrointestinal tract. Such are celiac disease, Crohn's disease and cystic fibrosis. They can interfere with the absorption of vitamin D from food. Surgical procedures, such as gastric bypass surgery, can also affect vitamin D absorption.
• Kidney or liver disorders also affect. The kidneys and liver play an essential role in converting vitamin D into its active form. Dysfunction or damage to these organs can interfere with the conversion process and lead to a deficiency.
• Certain medications, including anticonvulsants, glucocorticoids, antiretrovirals, and some weight loss medications, can affect vitamin D metabolism and contribute to a deficiency.

Author Ina Dimitrova