Vitamin D is on people’s minds a lot lately. There is always a renewed interest in the subject with the migration toward fall and winter, but this year, with the added concern over supporting the immune system through the COVID pandemic, and especially with uncertainty surrounding the return to school, it’s raising a lot of questions at the office. So here is a brief collective response.

How much to take for prevention? There is no one size fits all since people have various intake, sun exposure, and fat soluble vitamin metabolism. The more important question is : What is my target blood level ? There is some variation in the research but optimum is somewhere between 35-50 for healthy individuals. Some folks in health care push for higher levels for the average population, but in another blog I will share research that shows why that is not optimal for most people. It can take anywhere from 2000 IUs to 8000 IUs to achieve that level. My recommendation is to start between 2000 to 4000 IUs per day and test your blood levels after 6 weeks and adjust the dose accordingly. Be aware that there is an annual fluctuation with levels lowest around March for those of us in the Northern climate. Patients with active auto-immune illnesses or chronic inflammation do better is the blood level is somewhere in the 50-60 range.

How much to take during acute illness or when there has been a suspected infectious exposure? My recommendation is to take 10,000 IUs for the duration of the illness or for 7 days if asymptomatic.

What kind should I take? The active form of the vitamin, vitamin D3 is preferred over D2, but it needs to be taken daily for most people. Vitamin D3 is readily available everywhere and quite inexpensive, however you want to look for a brand that has as little added ingredients like fillers as possible. Vitamin D3 is a fat soluble vitamin and is best taken with a meal that has some healthy fats for optimal absorption. The liquid forms are easy to take for a lot of people, especially kids, and are pretty tasteless. When using vitamin D3 for immune support, especially mucosal immune support, taking it along straight vitamin A (not beta-carotene), and some essential fatty acids, is ideal. Since fat soluble vitamins control several metabolic processes as a group, I also recommend vitamin K2 along with vitamin D3 for patients who have reduced dietary intake (patients on strict dairy free diets who cannot have any aged cheese, or patients who do not eat fermented food on a regular basis). At the office I tend to use the liquid Apex vitamin D3 (2000 IUs per drop), and the Ultra D complex for the added vitamin A and DHA, and over the counter cod liver oil from a good brand (Carlson’s Nordic Natural) is a good option.