Do You Need a Vitamin D Supplement?

Vitamin D is popularly known as the sunshine vitamin as it is produced by our body when the sun hits the skin. It’s different from most other vitamins and is a steroid hormone which is produced from the cholesterol within our body. However, sun exposure may not provide an adequate amount of vitamin D, making it essential to obtain it from supplements or diet.

Even though there are a handful of foods that contain significant amounts of vitamin D, deficiency of this crucial vitamin is very common. Decreasing levels of vitamin D could be due to many reasons such as kidney dysfunction, lactose intolerance (milk allergy), inadequate absorption from the digestive tract or eating a vegan diet.

As per the National Institutes of Health (NIH), if your body has less than 12 nanograms per millilitre (ng/mL) of vitamin D, you may have a severe vitamin D deficiency. For our bones and overall health, if the body had less than 20 ng/mL it could be considered inadequate and may cause serious health issues like weakening of bones.

Who Are at Risk of Vitamin D Deficiency?

Vitamin D is a fat-soluble vitamin which is primarily essential for bone density in our body. There are two dietary forms of vitamin D. Vitamin D3 (cholecalciferol) is found naturally in animal foods like fish and egg yolks. Vitamin D2 (ergocalciferol) is found in plants, mushrooms and yeasts.

Vitamin D deficiency is quite common and some people are at a greater risk than others. People who are at a risk for vitamin D deficiency are −

  • People with chronic kidney disease or parathyroid disease.

  • People who have obesity.

  • Males and females on long-term steroids.

  • Post-menopausal females.

  • Elder people who are generally home-bound or in nursing homes.

  • Pregnant women and breastfeeding mothers.

How Much Vitamin D Should You Take?

Although the adequacy of vitamin D is measured at 20 ng/mL, health experts suggest that people should maintain higher than 30 ng/mL for disease prevention and optimal health. The Recommended Dietary Intake (RDI) for vitamin D as per age is measured in micrograms (mcg) or international units (IU). According to the National Institutes of Health Office of Dietary Supplements, the RDI for vitamin D should be −

  • 400 IU or 10 mcg for infants aged between 0 to 12 months

  • 600 IU or 15 mcg for children and adults aged between 1 to 70 years

  • 800 IU or 20 mcg for older adults and pregnant or breastfeeding women

Potential Health Benefits of Vitamin D

This fat-soluble vitamin may have some potential health benefits which are as follows −

  • Physical Strength − It may increase physical strength in the upper and lower limbs

  • May reduce risk of Osteoporosis − Adequate doses of vitamin D may help prevent osteoporosis, falls and fractures

  • Ease clinical Depression − Research suggests that vitamin D may ease symptoms of clinical depression

  • Cancer Prevention − Vitamin D may help reduce the risk of developing cancer.

  • Improved Mortality − This vitamin may minimize people's risk of dying at a young age and help them to live longer

  • Reduce the risk of type 1 diabetes − Research on infants stated that vitamin D may reduce the risk of developing type 1 diabetes in infants.

Many of these benefits are not backed by strong scientific evidence and hence more in-depth research is necessary to confirm many of these health benefits.

Vitamin D Supplements

Vitamin D supplements may aid in the prevention of certain health conditions but may not reduce the risk of developing them. However, if the body is not able to produce the required amount of vitamin D naturally, taking vitamin D supplements can be one of the best alternatives.

You can check your vitamin D level with the help of a blood test and this may help you understand if you are at risk of vitamin D deficiency. Vitamin D supplements could be beneficial for patients who have low levels and who may require vitamin D to maintain a normal serum level. Additionally, for older people vitamin D supplements may prevent softening of the bone (osteomalacia) and thereby minimize the risk of fractures. Vitamin D supplements may help in muscle function and cognition.

Healthcare providers may recommend taking around 400 to 800 IU of vitamin D3 per day as some studies have found it more effective as compared to vitamin D2. However, vegans may have to opt for a vitamin D2 supplement or a D3 supplement marked as vegan.

Generally, vitamin D3 supplements come from animal sources and hence, vegans may have to check thoroughly before taking them. Some researchers have found that the potency of vitamin d supplements may vary among brands. Some researchers have found vitamin D supplements with a USP mark more accurate as compared to others.

Combining Calcium and Vitamin D Supplements

This combination of calcium and vitamin D can work together to strengthen and protect your bones. Doctors may recommend postmenopausal women take calcium and vitamin D supplements together to prevent osteoporosis which increases the risk of fractures in old age. One research has also suggested that combining vitamin D supplements with calcium supplements may help to reduce the risk of developing cancer.

Vitamin D Toxicity or Overdosing

As vitamin D is fat-soluble, it is stored inside the body and may be harmful if the levels get too high. Vitamin D toxicity or hypervitaminosis D could be a result of high levels of vitamin D in the body. The symptoms of vitamin D toxicity are lack of concentration, drowsiness, confusion, constipation, high blood pressure, abdominal pain, depression and vomiting.

Nevertheless, this toxicity is very rare and may develop if you consume high doses of vitamin D supplements for extended periods. If you rely on your diet and sunlight for vitamin D, you are not at risk of overdosing. Your vitamin D supplements' dosage should not exceed 4000 IU per day.


Vitamin D is a fat-soluble vitamin which is produced within the body when it's exposed to sunlight. For people living in areas where they are not exposed to sunlight, vitamin D supplements can be an option to provide the body with an adequate amount of vitamin D. The deficiency of this vitamin is fairly common and with the help of a balanced diet or supplements, you can overcome it.

Getting vitamin D may help you maintain optimal health for a long time and if the body is not able to naturally produce this vitamin, taking the help of vitamin D supplements under a doctor's supervision may be beneficial.

Updated on: 16-Feb-2023


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