If you had zero sun exposure on significant areas of your bare skin, like most people, then research suggests it would require 9,600 IUs of vitamin D per day for most to reach 40 ng/mL, but individual requirements can vary widely, and you’ll need to get your levels tested to ensure you take the correct dosage required to get you into the optimal range.

The only way to gauge whether you might need to supplement, and how much to take, is to get your level tested, ideally twice a year, in the early spring, after the winter and early fall when your level is at its peak and low point. It’s important to note that vitamin D supplementation must be balanced with other nutrients, namely vitamin K2 (to avoid complications associated with excessive calcification in your arteries), calcium and magnesium

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It’s now known that vitamin D is necessary not only for healthy bones but for health throughout the body. As a powerful epigenetic regulator, vitamin D influences the activity of more than 2,500 genes, and vitamin D receptors are present all over the body, including in the intestine, pancreas, prostate and immune system cells. Vitamin D plays a role in numerous diseases, including:

• Cancer
• Diabetes
• Acute respiratory tract infections
• Chronic inflammatory diseases
• Autoimmune diseases such as multiple sclerosis

The single most important method of optimizing your vitamin D levels is exposing enough of your skin to the sun during around solar noon, which is 12 to 1 p.m. (depending on daylight saving time) in the summer. Be careful to never get burnt while understanding that the primary reason most people burn is that they have too much linoleic acid in their fat and that is the molecule the sun damages, which leads to burns and skin cancers.

Not only will regular sun exposure help to optimize your vitamin D levels but it will also increase melatonin in your mitochondria, which will decrease oxidative stress and increase energy production efficiency. It will also help to metabolize vitamin A and optimize your immune function.

B vitamins are also important for healthy immune function, which is your first line of defense against all infections and diseases, both acute and chronic. An August 2020 paper, “Be Well: A Potential Role for Vitamin B in COVID-19,”¹² made the case for B vitamin supplementation to minimize the risks associated with the infection.

B1, B2, B3, B5, B6, B9 and B12 can influence several COVID-19-specific disease processes, including viral replication and invasion, cytokine storm induction, adaptive immunity and hypercoagulability.¹³ In the graphic below, from the you can see which B vitamins are involved in each of these processes.

According to the authors, based on B vitamins’ effects on your immune system, immune-competence and red blood cells (which help fight infection), supplementation may be a useful adjunct to other COVID prevention and treatment strategies.¹⁴

“There is a need to highlight the importance of vitamin B because it plays a pivotal role in cell functioning, energy metabolism, and proper immune function,” they wrote.

“Vitamin B assists in proper activation of both the innate and adaptive immune responses, reduces pro-inflammatory cytokine levels, improves respiratory function, maintains endothelial integrity, prevents hypercoagulability and can reduce the length of stay in hospital.

Therefore, vitamin B status should be assessed in COVID-19 patients and vitamin B could be used as a non-pharmaceutical adjunct to current treatments …”

The paper goes on to detail how each B vitamin can be used to manage COVID-19 symptoms:

Advancing age can diminish your body’s ability to absorb B12 from food, so the need for supplementation increases as you get older. According to the National Institutes of Health,²⁰ the rate of vitamin B12 deficiency in the U.S. is close to 20% in those older than 60.

Other data from a large, nationally representative sample demonstrated that serum levels of B12 are inversely associated with obesity, so those who are overweight or obese also need to be more mindful about their B12 intake.

Vitamin B12 is found almost exclusively in animal foods such as beef and beef liver, lamb, snapper, venison, salmon, shrimp, scallops, poultry, eggs and dairy products. The few plant foods that are sources of B12 are actually B12 analogs that block the uptake of true B12, so do not make the mistake of thinking you can rely on vegan sources for all your B12 needs.

If you rarely eat the foods listed, consider using nutritional yeast. It’s high in B12 and has a cheesy flavor that can work well on any number of dishes. It’s highly recommended for vegetarians and vegans. One 16-gram serving (just over 2 tablespoons²²) provides 24 mcg of natural vitamin B12.²³

Sublingual (under-the-tongue) fine mist spray or vitamin B12 injections are also effective, as they allow the large B12 molecule to be absorbed directly into your bloodstream. To ensure optimal absorption and utilization, opt for the methylated version, i.e., methylcobalamin, as it is far superior and more natural than the more common cyanocobalamin.