Importance of Vitamin D

Krishna Sathishkumar
5 min readFeb 6, 2021


During the COVID-19 lockdown, my mother started feeling immense pain in her feet. She could barely move her legs. She also kept losing her balance. Her hands also started becoming very stiff. Her gait also became unsteady. We decided to consult a doctor over the phone (she had decided to close her clinic due to COVID-19 lockdown restrictions). The doctor suggested some multivitamin tablets and painkillers. But, despite this, the symptoms didn’t reduce.

Once the doctor re-opened her clinic, we visited her in her clinic. The doctor told us that a likely cause for her symptoms was Vitamin D deficiency. We took a Vitamin D test and found out that my mother’s Vitamin D level was less than 3ng/mL. This is far less than the recommended 30ng/mL. The doctor was surprised and said that she had never encountered such a patient before. The doctor asked my mother to get Vitamin D injections immediately. Now, my mother’s Vitamin D levels are normal and she is slowly recovering. Thus, it is important for us to understand Vitamin D and the vital role it plays in our lives.

Vitamin D is a fat-soluble vitamin that is naturally present in a few foods, added to others, and available as a dietary supplement. Vitamin D is unique because your skin actually produces it by using sunlight.

Vitamin D is necessary for building and maintaining healthy bones. That’s because calcium, the primary component of bone, can only be absorbed by your body when vitamin D is present.

Vitamin D deficiency can be caused by specific medical conditions, such as:

  1. Weight loss surgeries: Weight loss surgeries that reduce the size of the stomach and/or bypass part of the small intestines make it very difficult to consume sufficient quantities of certain nutrients, vitamins, and minerals.
  2. Obesity: A body mass index greater than 30 is associated with lower vitamin D levels. Fat cells keep vitamin D isolated so that it is not released. Vitamin D deficiency is more likely in obese people.
  3. Cystic fibrosis, Crohn’s disease, and celiac disease: These diseases do not allow the intestines to absorb enough vitamin D through supplements.
  4. Kidney and liver diseases: Kidney and liver play a key role in converting the Vitamin D obtained from sunlight or food from inactive to active form. Thus diseases in the kidney and liver can affect Vitamin D levels in the body

Other factors like age and skin color also play major roles in absorption of Vitamin D. The ability to absorb Vitamin D reduces with old age. People of darker skin absorb less Vitamin D when exposed to the same intensity of sunlight. People who rarely go outside are not able to use sunlight as a source of Vitamin D and thus have lower Vitamin D levels. This might have happened to many of us recently due to the COVID-19 lockdown restrictions.

Some medications like laxatives, steroids, cholesterol-lowering drugs, seizure-control drugs also reduce Vitamin D levels.

Scientists are studying vitamin D to better understand how it affects health. Vitamin D can have significant impacts on the following:

  1. Bone health and osteoporosis: Long-term shortages of vitamin D and calcium cause your bones to become fragile and break more easily. This condition is called osteoporosis. Millions of older women and men have osteoporosis or are at risk of developing this condition. Muscles are also important for healthy bones because they help maintain balance and prevent falls. A shortage of vitamin D may lead to weak, painful muscles. Getting recommended amounts of vitamin D and calcium from foods (and supplements, if needed) will help maintain healthy bones and prevent osteoporosis.
  2. Heart disease: Vitamin D is important for a healthy heart and blood vessels and for normal blood pressure. Some studies show that vitamin D supplements might help reduce blood cholesterol levels and high blood pressure — two of the main risk factors for heart disease.
  3. Depression: Vitamin D is needed for your brain to function properly. Some studies have found links between low vitamin D levels and an increased risk of depression.
  4. Multiple sclerosis: People who live near the equator have more sun exposure and higher vitamin D levels. They also rarely develop multiple sclerosis (MS), a disease that affects the nerves that carry messages from the brain to the rest of the body. Many studies find a link between low blood vitamin D levels and the risk of developing MS.
  5. Type 2 diabetes: Vitamin D helps your body regulate blood sugar levels. Thus people with low Vitamin D levels are at a higher risk of developing Type 2 diabetes.

Rate of Vitamin D production can be increased by taking walks in bright sunlight. Vitamin D can also be obtained in limited amounts from certain foods such cod liver oil, red meat, egg yolk, fortified cereals, juice, and milk, etc. Vitamin D content for different foods is given in the table below.

The recommended daily amount of vitamin D is 400 international units (IU) for children up to age 12 months, 600 IU for ages 1 to 70 years, and 800 IU for people over 70 years. Food and Sunlight may not be able to satisfy these requirements. Vitamin D supplements or injections can be taken to increase Vitamin D levels. Taken in appropriate doses, vitamin D is considered safe. But excess dosage can cause toxicity, which can cause confusion, depression, vomiting, high BP, or in extreme cases, liver failure.

This article provides information that should not take the place of medical advice. You must talk to your healthcare providers (doctor, registered dietitian, pharmacist, etc.) about questions regarding Vitamin D and what may be best for your overall health.





Krishna Sathishkumar

I am interested in Health and Medicine. I want to use Medium as a medium to spread my ideas.