Vitamin D Deficiency: Causes, Signs and Symptoms

Vitamin D is a fat soluble vitamin. It is particularly essential for bone health and functioning of the immune system in our body. Vitamin D helps our body absorb calcium and phosphorus, and maintain strong bones and teeth.

     The Common Causes of Vitamin D Deficiency are:

• Lack of exposure to sunlight 
• Dietary deficiency of vitamin D 
• Liver and kidney diseases 
• Poor food absorption in cystic fibrosis and Crohn’s disease, and in patients who have undergone gastric bypass surgery 
• Use of certain medicines, including phenytoin, phenobarbital, and rifampin etc can cause vitamin D deficiency 
• In infants who are exclusively breastfed. Formula milk is fortified with vitamin D.

The Common Signs and Symptoms of Vitamin D Deficiency are:

• Frequent bone fractures due to thinning and brittle bones
• Bone and back pain
• Frequent infections
• Feeling exhausted or tired
• Mood swings with anxiety or depression
• Impaired wound healing

Health Risks Associated with Vitamin D Deficiency

Vitamin D deficiency can result in serious health conditions like Osteomalacia in adults, Rickets in children and Osteoporosis. 

Osteomalacia is a characteristic feature of vitamin D deficiency in adults. Osteomalacia is softening of the bones due to demineralization (the loss of mineral) and most notably by the depletion of calcium from bone. Vitamin D deficiency in children can result in Rickets. Rickets results in softening and bending of bones. Osteoporosis is a condition of fragile bones with increased susceptibility to fracture. Vitamin D and calcium deficiency are one of the leading causes of osteoporosis.

Research is also being conducted to study the possible relation of Vitamin D with several medical conditions, including diabetes, hypertension (high blood pressure), cancer, and autoimmune conditions such as multiple sclerosis. But, it will be too early to comment anything on this.

Vitamin D is derived from endogenous sources and exogenous sources.

Endogenous source: It is produced in our body on exposure of our skin to sunlight. 

Exogenous source: Dietary sources of vitamin D include fish, eggs, fortified dairy products and dietary supplements.

Vitamin D requirements depend on a number of factors like age, race, geographical location, season, sun exposure etc. A daily Vitamin D intake of 1000–4000 IU, or 25–100 micrograms, should be enough to ensure optimal blood levels in most people. 

In case you are Vitamin D deficient,  you can treat this condition by getting more Vitamin D through diet and supplements. Increased exposure to sunlight also helps as Vitamin D is produced in our body on exposure of skin to sunlight. 

Consult your doctor to know about how much Vitamin D supplements you need to take, how often you need to take it, and how long you need to take it in case you are Vitamin D deficient.

Excess supplementation of Vitamin D can result in Vitamin D intoxication. Vitamin D levels can easily be monitored by a simple Vitamin D blood test. 

The normal range of Vitamin D 25-OH is measured as nanograms per milliliter (ng/mL) or nmol/L and can vary from lab to lab.

Level

Reference range (ng/mL)

Severe deficiency <10 ng/mL

Mild to moderate deficiency 10-24

Optimal 25-80

Potential intoxication >80

Note:

·      There can be seasonal variation in 25 (OH) vitamin D level, with values being 40-50% lower in winter than in summer. It is also influenced by sunlight, latitude, skin pigmentation, sunscreen use, and hepatic function.

·       25 (OH) vitamin D levels can vary with age

·       25 (OH) vitamin D level is increased during pregnancy.