Managing a vitamin D deficiency - Symptoms, diagnosis, causes, and treatment

Time to read 8 min

Vitamin D is one of the most important vitamins in the body, and is a fat soluble vitamin that the body produces after exposure to the sun (specifically through UVB photons). After consumption, through diet or Vitamin D supplements, it is converted into an active form called 25-hydroxyvitamin D [25(OH)D] or calcidiol.

It helps the body absorb and retain Calcium and Phosphorous which are vital for bone health and growth. Optimal levels of Vitamin D can also reduce cancer cell growth, control infections, and reduce inflammation in the body.

Some of the organs and tissues in our body also have receptors for Vitamin D, which means that a deficiency in the vitamin can impact our health at the organ level. Its function is to promote bone health, optimize cardiac functioning, improve immune system performance, and promote muscle development, among other areas.

Why Vitamin D is key to healthy living

Vitamin D plays a multifaceted role in our health and wellbeing. Not only can we include Vitamin D through our diet, but our body converts sun light into Vitamin D naturally as well.

That is why it is advisable to get enough sun exposure regularly to avoid the symptoms of inadequate Vitamin D levels. We should get enough vitamin D in our body to ensure optimal performance of our various systems.

Vitamin D plays a key role in the following functions -

Strengthening bone health

One of the main objectives of Vitamin D is to enhance the absorption of Calcium in our body. A vitamin D deficiency can lower our ability to absorb the mineral, which can lead to issues with weak bones and lower ability to heal injuries.

Promoting muscle development

A Vitamin D deficiency in children and adults can also cause issues with poor muscular development, atrophy, and healing in muscle injuries. For those with an active lifestyle, getting enough vitamin D is vital to optimal recovery.

Modulation of immune system

Vitamin D plays a critical role in managing the immune system, as it has both anti-inflammatory and immunoregulatory properties. It is also important for the activation of defences against infections that can impact our immune system.

Enabling cell-growth

Vitamin D is known to have pleiotropic or secondary effects than calcium absorption. Genes with Vitamin D receptors influence cell development, cycling, and proliferation in the body. This can holistically impact our bodily functions, beyond strengthening our bones and muscles.

Lowering inflammation in the body

Rheumatoid arthritis, psoriasis, and other inflammatory diseases can be connected to low Vitamin D levels in the body. You can be at risk of inflammatory diseases if your diet and lifestyle aren't optimized for Vitamin D absorption.

Regulating cardiac health

The performance of the heart and the overall cardiac system is also connected to Vitamin D. How much vitamin D is present in the body can impact your risk for heart disease, stroke, hypertension, and other cardiovascular diseases. 

Symptoms of Vitamin D deficiency in the body

You can experience multiple symptoms of Vitamin D deficiency before realizing that the root cause is lower levels of the vitamin in the body. You can experience depression, bone weakness, muscle atrophy, and chronic headaches due to severe vitamin D deficiency. The risk of other disease factors also rises when the vitamin D level in the body is not optimized.

Chronic fatigue

People that are experiencing chronic fatigue should get their Vitamin D levels tested. A lack of energy is a clear sign of a Vitamin D deficiency.

Frequent illnesses or constantly sick

Vitamin D plays a vital role in immune system management, which is why lower Vitamin D levels can make it more difficult to recover from illnesses or make you fall sick more often.

Painful joints or bone pain

Pain in the bones and joints is another clear Vitamin D issue. Back pain is a common symptom that many people experience as well. This can also lead to fractures not healing properly, long-term pain in joints, and higher risk of osteoporosis and arthritis.

Muscle weakness or pain

Muscle weakness and sensation of tiredness after routine activities can be a sign of Vitamin D deficiency. It is best to get a comprehensive test done to find root cause.

Depression or signs of mood swings

Depression is another important sign of Vitamin D deficiency, along with other factors. Low Vitamin D levels can also cause symptoms of anxiety in individuals who also don't get enough natural sun exposure.

Fluctuations in weight

Sudden fluctuations in weight and energy levels can also be a sign of Vitamin D deficiency in the body. Weight management, hormonal regulation, and organ performance are interlinked with Vitamin D levels.

It is important to optimize the sources of Vitamin D to absorb as much of the vitamin as naturally possible. A vitamin D supplement is also an ideal strategy to improve our source input of the vitamin. Taking a nutrition deficiency test can also give us more insights on what symptoms may be connected to what vitamin levels.

Factors that can create a Vitamin D deficiency

Whether there is vitamin D deficiency in the body can also be determined by specific risk factors involved.

  • Dietary risk factors, such as too much fried food, lack of calcium and vitamin D, and consuming foods that are processed rather than fresh.
  • Lifestyle factors, such as excessive drinking, smoking, lack of quality sleep, sedentary lifestyle, etc.
  • Poor access to sunlight can also be a factor for risk of vitamin D deficiency.
  • Pollution in the air can block UVB rays and prevent them from being absorbed through the skin.
  • Absorption issues can also arise if the person has Crohn's disease or celiac disease, which can decrease our ability to absorb Vitamin D from diet.
  • Kidney & liver health are also important to absorbing Vitamin D through diet. The amount of vitamin D absorbed could be significantly lesser than supplemented.
  • Other factors, such as pregnancy, high stress, age, and skin type can also impact how much Vitamin D is absorbed naturally. 

Diagnosing a Vitamin D deficiency

If you are experiencing symptoms of Vitamin D deficiency, then it is best to get tested immediately. You should not take these symptoms lightly or wait for your levels to improve before taking a test for Vitamin D deficiency.

A vitamin D deficiency is a serious health risk factor that can lead to other conditions such as heart disease, diabetes, infections, and some cancers.

Conducting a Vitamin D blood test would be the right strategy to measure and diagnose a deficiency. You can order a home test kit to measure the levels of vitamin D in the body. While a normal range of serum 25(OH)D levels would be 30–100 ng/mL, it is best to get tested multiple times a year to ensure that they are rising if lower.

At the same time, if your levels are above 100 ng/mL, then you should reduce your Vitamin D exposure by limiting supplementation and direct sun exposure. Too much vitamin D is also harmful to the body and will need to be reduced through strategic measures.

A healthy range is also dependent on other Vitamins, which is why it is important to get a complete vitamin blood test done to check for all deficiencies in the body.

Treatment protocol for Vitamin D deficiency

Vitamin D is a key element involved in the proper functioning of our body. The effects of vitamin D deficiency can be managed through the right supplementation and medical interventions. The right doses of vitamin D from the sun or our diet can help people with emerging symptoms of deficiency.

High dose medication for Vitamin D

If you have a vitamin D deficiency, then your doctor may prescribe a high dose medication for improving levels. Since Vitamin D is a fat soluble compound it can be supplemented in the body via tablets or liquid form.

Slow dose Vitamin D

If your levels aren't too low or in the dangerous zone, then your doctor may prescribe a lower dose tablet, powder, or liquid. The slower dose helps the body assimilate vitamin D better, as you improve your diet and lifestyle for long-term optimization.


This is ideal for faster recovery from Vitamin D deficiency and can help improve levels for around 6 months. It needs to be accompanied by maintenance therapy and regular testing to ensure optimal levels. 

What are the best sources of Vitamin D?

Some of the best sources of Vitamin D are as follows -

Nutritional sources of Vitamin D

One of the most important sources of Vitamin D in the body is through nutrition. You can opt for Vitamin D rich foods, such as fish, meat, eggs, dairy, leafy vegetables, and fortified foods. By avoiding processed foods and opting for high-value nutritional meals, you can naturally improve a low level of Vitamin D.

Supplementation of Vitamin D

By choosing a high quality supplement for Vitamin D, we can also improve low levels of the vitamin. It is important to get a complete vitamin profile done, through home tests, to understand whether a single supplementation is required or a more general one.

Exposure to sunshine

The body needs access to UVB rays emitted by the sun, that interact with a protein 7-DHC in the skin and convert it into vitamin D3. Access to the right amounts of sunlight is also key, which is why the morning sun is considered the best option to improve Vitamin D levels in the body.

How much vitamin D do you need per day?

The daily IU of vitamin D depends on your age, lifestyle, and exposure to sunlight.

For teens (14-18 years)

Around 15 mcg or 600 IU is required for optimal functioning.

For adults (19-70 years)

Around 15 mcg or 600 IU is required for optimal functioning and to avoid risk of disease, health issues, etc.

For seniors (71 + years)

Around 20 mcg or 800 IU is recommended for longevity, healthy living, and optimal organ performance.

For pregnant and breastfeeding women

Around 15 mcg or 600 IU is recommended for hormonal management, optimal milk production, and overall strength.

On average, diet or vitamin D supplementation of around 600-700 IUs can allow your body to function normally long-term. These numbers can also vary for people who have secondary conditions, which limits their vitamin D absorption or those who are deficient in vitamin D. Additionally, those with vitamin D deficiency and limited exposure to sunlight may be needing more.

 *Medical Disclaimer - The following information is for educational purposes only. No information provided on this website, including text, graphic, and images, are intended as substitutes for professional medical advice. Please consult with your doctor about specific medical advice pertaining to your condition(s) 

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