Perhaps you've decided against getting the flu vaccine either because you don't think it's effective, you think it may actually be harmful, you think the widespread panic is mostly hype over what will inevitably be just another flu, or for any number of anti-vaccine reasons we've heard in the last few weeks. Whatever your decision, you may want to do something to protect yourself and a glass of orange juice with breakfast probably doesn't constitute an effective overall health strategy. What to do?

Ladies and gentlemen, I present vitamin D. There has been a great deal of research centered around vitamin D as of late, and for good reason - it has been discovered that this "vitamin" (which is actually a powerful steroid hormone precursor) is a vital nutrient necessary for many life processes not previously known. Vitamin D was discovered some time ago to play a powerful role in maintaining bone density and preventing osteoporosis and has recently been hypothesized to play a role in prevention of dementia. Other studies have found vitamin D to play a preventative role in "heart disease, hypertension, arthritis, chronic pain, depression, Iinflammatory bowel disease, obesity, premenstrual syndrome, muscular weakness, fibromyalgia, Crohn's disease, multiple sclerosis, autoimmune illness, and cancer". It even plays an important, although unknown role in weight loss.

That's great and all, but what about the flu? Vitamin D has also been found to play an profound role in the immune system. It is an immune system modulator, preventing the over-expression of inflammatory cytokines. It also controls the expression of anti-microbial peptides, which may be where its importance against the flu comes into play. These anti-microbial peptides are present in the cells that line the respiratory tract, as well as in immune cells themselves. This gives a potent defense against flu and other respiratory invaders - and they're stimulated by vitamin D. No vitamin D, no anti-microbials killing off flu viruses.

In fact, researchers speculate that lowered vitamin D rates from lack of sunlight in the winter may be what actually leads to a "flu season" in the first place. Past studies have found that ultraviolet radiation (from sun lamps or directly from sunlight) lowers the incidence of respiratory infections from viruses, as does supplementing with cod liver oil (which contains vitamin D). Paraphrasing nutritionist Byron Richards, while to blame all of the flu on vitamin D deficiency is a stretch as is suggesting that taking vitamin D is going to prevent everyone from getting the flu, "a lack of vitamin D is one factor that is easy to change and likely to contribute to a population of citizens less likely to rapidly spread the flu from one to another, in addition to helping individuals fight the flu or get a less severe case of the flu."

So how does one up their vitamin D levels? Vitamin D is thankfully provided by the sun for free! While sunbathing is chastised due to the increased possibility of developing carcinogenic melanoma, few experts have looked at the repercussion to vitamin D levels of staying out of the sun and always applying sunscreen. Many experts consider this to be a drastic oversight and feel that at least some unhindered sun exposure is necessary daily.

Certain foods also have vitamin D, but not many that exist in the plant world. You can find natural occurring vitamin D in shiitake and button mushrooms, fish like mackerel, salmon, herring, sardines, catfish and tuna, or from eggs. As mentioned above, you can also get it from supplementing cod liver oil (I guess grandma was right about that one!). Note that foods that have been fortified with vitamin D, like milk, soy milk and cereals, are not the best choice. Fortified foods usually use vitamin D2 instead of vitamin D3 which is the kind made by your skin and is the more effective of the two. As well, fortified foods often do not provide enough vitamin D to compose a comprehensive health strategy.

But some doctors and nutritionists feel that the amount of vitamin D one gets from foods and the minimal sun exposure of the Western world is really not enough to maintain ideal levels for fighting off flu. In the past, when our ancestors worked outside during the day, the sun was an adequate source of vitamin D. Today, however, we've all moved indoors for most, if not all, of the day especially in cooler months. As a result, taking supplements of vitamin D may be a necessity.

Some may be surprised to find many nutritionists recommending between 1,000 to 5,000 IU per day, and some even going much higher. The Recommended Daily Intake (RDI) of vitamin D (200 to 600 IU per day), while possibly sufficient for preventing the bone diseases like rickets or osteoporosis, is too low to prevent many of the diseases now being discovered to be affected by vitamin D levels. Indeed, many scientists are calling for an increase in the official RDI for vitamin D in order to help combat what is being called a "Vitamin D Deficiency Crisis".

Dr. Russle Blaylock, recommends 5,000 IU of vitamin D3 for adults (as does Dr. John Cannell, MD, of the Vitamin D Council) and 2,000 for children or pregnant women to protect against the flu. Blaylock recommends bumping that up to 20,000 IU to counteract the possible side effects of the swine flu vaccine if you decide to get the jab. Dr. Joe Prendergast reportedly has his patients on levels as high as 50,000 IU per day for everything from stroke and heart attack prevention and recovery to rheumatoid arthritis and diabetes. Prendergast claims these levels of supplementation are perfectly safe and, more importantly, effective (although, note that Dr. Prendergast's patients who are on these levels of vitamin D3 are under the watchful eye of a physician. Be sure to consult your health care practitioner before considering taking levels this high).

When supplementing, most doctors recommend that you get your blood levels of vitamin D3 checked every 3 months or so to make sure you're not over-supplementing and to make sure the dosage you're taking is effective at getting your blood concentrations to the appropriate level. While it looks as though vitamin D3 is safe up to very high levels, vitamin D2 may actually have a much lower level of tolerance. 10,000 IU of vitamin D3 is what is provided by a single 20-30 minute session of sunlight, so many researchers feel this level of supplementation is perfectly safe.


The Healthy Foodie is Doug DiPasquale, Holistic Nutritionist and trained chef, living in Toronto. You can email him with questions at dugdeep@gmail.com.