The role of vitamin D in human health and immunity continues to grow and evolve. Evidence has recently emerged showing that in countries like Spain and Italy, which have one the highest rates of vitamin D deficiency have experienced some of the highest rates of COVID-19 infection and mortality in the world. Despite adequate sunlight year-round, both these countries have no formal policy for vitamin D food fortification and supplementation. Compared to countries like Norway and Finland, which have far less sun exposure but have higher levels of vitamin D because of recommendations for food fortification and supplementation have thus far had much less infection and deaths from Covid 19.
Yes, we all need to be outdoors and experience sunlight, which is needed by the body to make vitamin D. However, it has been difficult to recommend a specific amount of time in the sun that is safe and reliable for everyone. When compared to vitamin D supplementation, studies have shown that sunlight exposure is indeed an unreliable method of raising vitamin D levels as well as eating foods high in vitamin D (such as salmon, tuna, sardines, cow's milk, fortified beverages like soy, almond, etc., eggs, and mushrooms).
Among many functions such as bone density, blood sugar management, cardiovascular, muscular, and mental health, vitamin D is critical for bolstering immunity against infection and controlling excessive pain and inflammation. Indeed, numerous studies have shown vitamin D status and supplementation translate to less respiratory viral infections and complications with quicker recovery times from colds and flu.
Health Canada has set the safe upper limit of Vitamin D supplementation at 4,000 IU per day for individuals 9 years of age and older. For children ages 4 to 9 the upper limit is 3,000 IU, for children ages 1 to 3 it is 2,500IU, for infants 7 to 12 months it is 1,500 IU, and infants 6 months and younger it is 1,000 IU of vitamin D. Older individuals (>50 years of age), those with autoimmune/chronic disease states such as diabetes, asthma, osteoporosis, and cardiovascular disease and individuals at higher risk of respiratory infections may require vitamin D supplementation towards the higher range or even more. However, because an adequate dose of vitamin D varies from individual to individual it is best to consult with your health practitioner.
Farid Wassef BSc Pharm, RPh Stouffville IDA Pharmacy firstname.lastname@example.org