Thursday, May 23, 2024

How Vitamin D Can Help Bolster Your Immune System And Knock Down Disease

We often hear about how vitamin D helps our body absorb calcium. While it is a key player in bone health, that is not the only role it has in our body. In fact, almost every cell has a vitamin D receptor.1.

Eggs are a natural source of vitamin D.

Vitamin D influences the bones, intestines, immune and cardiovascular systems, pancreas, muscles, and brain.It is a fat soluble vitamin that is naturally present in a limited amount of foods. Our body can also produce vitamin D from the sun.2 The vitamin D we obtain through food or via the sun needs to be converted by the liver and kidneys into an active form before it can be used.2 However, as we age our body becomes less efficient at these conversion processes.3,4.Our ability to absorb vitamin D from food also lessens, further increasing the risk of vitamin D deficiency with age.2

Sardines are rich with vitamin D.

Even though there is no shortage of information on the importance of vitamin D, almost 50 per cent of the world’s population has a deficiency.Symptoms for deficiency are often subtle and difficult to recognize, but can have a significant negative impact on overall quality of life. If you find that you are often sick with a cold or flu, low vitamin D levels could be a contributing factor.

Or perhaps you just can’t shake feeling tired? This could also be a subtle and often overlooked symptom of a vitamin D deficiency.6 Some other symptoms can present as chronic back aches, low mood or even slow healing of cuts.2-6 While the symptoms are often vague, a simple blood test can help determine if vitamin D deficiency may be a contributing factor.

The daily recommendations for vitamin D intake are 600 IU for children and adults 9-70 years old and 800 IU for adults over the age of 71.In Canada, where you will find vitamin D present in food is primarily those that have been fortified.such as cow’s milk and milk alternatives. Natural food sources are limited – the most frequently consumed are egg yolks and fatty fish like salmon and sardines.7

Look for milk products fortified with vitamin D.

One of the most common questions is ‘Should I take a supplement?’ While it can be difficult to obtain enough vitamin D from food alone, it is not impossible. However, with the natural aging process, it can become even more challenging. Studies suggest that supplementation is the best way to ensure adequate vitamin D intake to meet needs.4 The recommended dose should be discussed with your doctor or registered dietitian to ensure you are not taking too much. Health Canada recommends supplementing with 400 IU daily if over the age of 50,8 but many health care providers suggest that 1000 IU daily is generally regarded as safe.3-4 The addition of any new supplements should always be discussed with your doctor prior to taking.

If you are looking for help to optimize your vitamin D intake, your Shoppers Drug Mart and Wellwise registered dietitians are available for personalized nutrition advice tailored to your health needs. For more information, visit or to book your appointment today.

Jemma Besson is a Registered Dietitian and Certified Diabetes Educator who works for Shoppers Drug Mart®.

The information provided is for personal use, reference and education only and is not intended to be a substitute for a Physician’s advice, diagnosis or treatment. Please consult your healthcare professional for specific information on personal health matters. Please note: Dietitian services are currently only available in select Ontario stores. Please contact your store to learn more. ®/TM 911979 Alberta Ltd. ©2019 Shoppers Drug Mart Inc


  1. Nair, R and Maseeh, A. (2012). Vitamin D: The “sunshine” vitamin. Retrieved from
  2. National Institutes of Health. (2019). Vitamin D: Fact Sheet for Health Professionals. Retrieved from
  3. Boucher, B. (2012). The Problems of Vitamin D Insufficiency in Older People. Retrieved from
  4. Meehan, M and Penckofer, S. (2014). The Role of vitamin D in the Aging Adult. Retrieved from
  5. Schwalfenberg, GK. (2010) A review of the critical role of vitamin D in the functioning of the immune system and the clinical implications of vitamin D deficiency. Retrieved from
  6. Johnson, K. and Sattari, M. (2015). Vitamin D deficiency and fatigue: an unusual presentation. Retrieved from
  7. Unlock Food (2019). What you need to know about vitamin D. Retrieved from
  8. Health Canada. (2019). Vitamin D and Calcium: Updated Dietary Reference Intakes. Retrieved from



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