Vitamin D Deficiency, Signs, Symptoms, Causes, Treatment and Management. d deficiency

It is ironic how in a country like India with abundant sunshine, a huge number of people experience a (VDD) vitamin D deficiency. Yes, what’s surprising is how several studies have found the following statistics

  • 2018: Study in Journal of Medicine and Family Care: 40% to 99%, people from all age groups had a vitamin D  deficiency
  • 2018: Study in ANN Hum Bio: The prevalence of VDD was high among the urban elderly population in the south Indian city of Hyderabad.
  • 2022: Study in BMC Health: India figured among top 3 South Asian countries with high levels of VDD topped only by Pakistan and Bangladesh
  • 2023: Studies Reported by Tata 1 mg: 76% of Indian suffer from VDD
  • 2023: Stat Pearls: 1 billion people and around 50% of the global population has vitamin D insufficiency.

Why are Indians not getting enough vitamin D? Is it a fear of going out in the sun or is the new trends of work from home post Covid that is depriving Indians from this free sunshine vitamin. According to Indian studies, Vitamin D is a silent epidemic affecting both the rich and the poor alike.

While the underprivileged do not get enough vitamin D due to a major vegetarian diet, the rich are now consuming more processed food equally inadequate in the vitamin. This is also why so many adolescents are found lacking in vitamin D. The main dietary sources of Vitamin D are fish, fortified food, and supplements. Vegetables and grains are poor sources. Read on to know about vitamin D and signs of  vitamin D deficiency.

What is Vitamin D?

Among most essential nutrients, vitamin D stands out as a powerhouse with a multitude of benefits for the human body. Often referred to as the “sunshine vitamin,” it plays a crucial role in various physiological processes such as contributing to bone health and preventing disease like osteoporosis.

Vitamin D is a fat-soluble vitamin that exists in two main forms: vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol). While vitamin D2 is primarily derived from plants, vitamin D3 is the form synthesized by the skin when exposed to ultraviolet B (UVB) sunlight. Both forms can also be obtained from certain foods and supplements. Scientifically speaking, vitamin D is more of a hormone rather than a vitamin which helps the body to absorb calcium and phosphate from the gut into the blood. It also prevents calcium loss from the kidneys.

Metabolism of Vitamin D

The unique aspect of vitamin D lies in its ability to be synthesized by the body through exposure to sunlight. It is our liver and kidneys which convert Vitamin D procured from the sun and diet into calcitriol or 1,25-Dihydroxyvitamin D3, an active form of Vitamin D that the body can use.

Key Benefits of Vitamin D  11/81/59

  • Bone Health: Vitamin D facilitates the absorption of calcium and phosphorus, vital minerals for maintaining strong and healthy bones. A deficiency in vitamin D can lead to conditions like osteoporosis and rickets, particularly in children.
  • Immune System Support: Vitamin D regulates the immune system helping the body defend against infections and immune responses. It also reduces the risk of autoimmune diseases and chronic inflammation.
  • Mood Regulation: Research has proven links between vitamin D levels and mental health where adequate vitamin D reduces the risk of depression and mood disorders. Studies suggest that vitamin D helps the body produce serotonin, a neurotransmitter that contributes to feelings of well-being.
  • Cardiovascular Health: Vitamin D helps regulate blood pressure, reduce inflammation, and improve overall heart function. Maintaining optimal levels may contribute to a lower risk of cardiovascular diseases.
  • Cancer Prevention: Some studies have indicated that sufficient vitamin D levels may be associated with a reduced risk of certain cancers, including breast, prostate, and colon cancers. However, further research is needed to establish conclusive evidence.

What Is the Optimal Level of Vitamin D

There is a mixed response to what ideal levels of Vitamin D should be which is why there is a possibility of people overdosing on vitamin D. However, the general opinion is as follows.

Amount               Category

less than 30 nmol / L:                    Deficiency

30 to below 50 nmol / L:               Inadequate

50 to 124 nmol / L:                         Adequate

over 125 nmol / L:                          Too high

Diagnostic labs have different reference ranges and a result should be read accordingly. Your doctor will be the best person to decide if you are lacking vitamin D or not. 

How is vitamin D Regulated? 

Vitamin D or calcitriol is regulated by various factors in the body including parathyroid hormone or PTH. When calcium levels in the blood are low, the parathyroid glands release PTH. PTH stimulates the kidneys to produce more calcitriol, which, in turn, helps increase calcium absorption in the intestines. The increase signals the parathyroid glands to stop producing PTH. Vitamin D is also regulated by calcium, phosphate, and calcitriol.

What causes vitamin D deficiency?

  • Poor nutrition
  • Malabsorption of vitamin D
  • Not enough sunlight
  • The Liver or kidneys cannot convert vitamin D to its active form
  • Underlying conditions like Crohn’s or Celiac disease that impairs vitamin D absorption
  • Medication that interferes  with the body’s ability to convert or absorb vitamin D
  • Obesity

Signs of Vitamin D Deficiency

Bone and Muscle Pain

Vitamin D plays a crucial role in helping the body utilize calcium and phosphorous  to build bones and support healthy tissues. A deficiency can lead to bone and muscle pain, including back pain and muscle weakness. Vitamin D deficiency can decrease calcium and phosphorous absorption causing hypocalcemia, and secondary hyperparathyroidism or overactive parathyroid glands. Individuals with insufficient vitamin D levels may also experience fatigue, muscle weakness, and a general lack of energy.

Mood Changes

Vitamin D is linked to serotonin production, a neurotransmitter that contributes to mood regulation. Deficiency may be associated with mood disorders, such as depression and seasonal affective disorder (SAD).

Impaired Wound Healing

Vitamin D is important for the immune system and can affect the body’s ability to heal wounds.

Frequent Infections

A weakened immune system due to VDD may result in an increased susceptibility to infections and illnesses.

Hair Loss

There is some evidence to suggest that vitamin D may play a role in hair follicle health, and deficiency could contribute to hair loss.

Bone Deformities (in Children)

Severe and prolonged VDD in children can lead to rickets, a condition characterized by soft and deformed bones. A typical manifestation in children is bowed legs.

Joint Pain and Muscle Cramps

Inadequate levels of vitamin D may be linked to muscle cramps and spasms. Vitamin D is also involved in maintaining joint health, and deficiency may contribute to joint pain and inflammation. Moreover, VDD is also associated with a tingly, “pins-and-needles” sensation in the hands or feet although this could also be caused by other underlying conditions.

Poor Cognitive Function

Some studies suggest a potential link between low vitamin D levels and cognitive decline, though more research is needed in this area.

Increased Pain Sensitivity

Vitamin D influences the pain pathways associated with cortical, immunological, hormonal, and neuronal changes. The strongest association between vitamin D deficiency and pain is reported to occur in leg muscles.


While there are several other reasons including genetics that cause hypothyroidism, several studies have found a definite association between VDD and thyroid function.

How is vitamin D deficiency diagnosed?

There aren’t any marked symptoms of VDD which is why diagnosing it is difficult. Not always is a blood test ordered for all patients simply because the symptoms could be due to other conditions as well. However, if you are repeatedly experiencing muscle and joint pain, a blood test is the best way to find out if you are lacking in vitamin D.

How is vitamin D deficiency treated?

The recommended daily amount of vitamin D is 400 international units (IU) for children up to age 12 months, 600 IU for people ages 1 to 70 years, and 800 IU for people over 70 years. While consuming foods rich in vitamin D is good, it might not be enough to correct the VDD which is why your doctor might prescribe a supplement more than the RDA to correct vitamin D deficiency. The dosage of vitamin D depends on age, weight, and severity of symptoms with doses ranging from weekly to monthly rather than daily. If you are a healthy individual who gets adequate sunlight, you probably don’t need to supplement with vitamin D. It is not advisable to dose yourself without consulting a doctor.  Here are some natural sources of vitamin D.

  • Sunlight: The best way to get your vitamin D is by spending 10 to 30 minutes in the sun at least twice a week. This will stimulate adequate vitamin D production. However, factors such as geographical location, skin pigmentation, and the use of sunscreen can impact how your body absorbs vitamin D. Some studies say that the best time to get vitamin D from sunlight in India is between 11 am to 2 pm at a time when your shadow is the shortest. Just 15-20 minutes would be sufficient to get your RDA of vitamin.
  • Fatty Fish: Fatty fish like salmon, mackerel, and sardines are excellent dietary sources of vitamin D3. Consuming these omega-3 rich fishes not only supports heart health but also contributes to maintaining optimal vitamin D levels.
  • Fortified Foods: Due to the limited natural dietary sources of vitamin D, many foods are fortified with this essential nutrient. Fortified milk, orange juice, cereals, and certain plant-based milk alternatives often contain added vitamin D.
  • Egg Yolks: Egg yolks are a good source of vitamin D, particularly if the eggs are sourced from pasture-raised chickens. Including eggs in your diet provides a natural and readily available form of this vital vitamin.
  • Supplements: In cases where it is challenging to obtain sufficient vitamin D from sunlight and dietary sources, supplements can be a convenient and effective solution. It is advisable to consult with a healthcare professional to determine the appropriate dosage, as excessive vitamin D intake can lead to toxicity.

Vitamin D, the sunshine vitamin, plays an integral role in maintaining the overall health and well-being of the human body. From supporting bone health to regulating the immune system and influencing mental well-being, it has a huge impact on health. This is why, when symptoms of vitamin D deficiency are evident, it is advisable to get a vitamin D test done. Beyond that, spending time outdoors is good not just for vitamin D but your overall health and well-being.