To take more than 1000 IU/day or not, that is the question. How much should we be taking? Recently, some research was released suggesting that Canada’s (and the USA’s) current vitamin D recommendations are too low due to some statistical errors that were made when calculating the RDA for vitamin D. If this is true, it could have serious implications for the health status and disease risk of Canadians. After reviewing the evidence and the error claims put forth, the IOM (Institute of Medicine in the US) and Health Canada concluded that no error was made in the statistical calculation
Almost one-quarter of Canadians suffer from seasonal allergies or allergic rhinitis. Allergy season can last (depending on geographic location) in Canada anywhere from early February (mostly the west coast) to the first frost of the year (October – November, depending on region).
Certain allergies are also seasonally dependent and are at their prime at different times of year. With it currently being late summer and entering into fall, typically ragweed is the chief culprit for allergy sufferers. The plant produces large amounts of pollen and releases it super quickly. Ragweed likes to grow in disturbed soil, which is typically soil that has been altered from its natural state. This is bad news for city dwellers, as construction, slightly warmer micro-climate, and earth moving activities typically carried out in urban settings potentiate “disturbed” soil and thus, can cause ragweed to grow faster and larger.
Interestingly, the worst cities in Canada for allergies typically tend to be larger urban environments – Edmonton, Toronto, Vancouver, Windsor, Halifax and surprisingly Yellowknife. So especially for you city slickers, here are some natural therapies to possibly aid in your fight against seasonal allergies.
1. Butterbur also known as Petasites.
Dr McIntyre’s previous blog post goes into detail about why this is definitely number 1 on the list (Spring has Sprung Have your Allergies Sprung Too?)
In short, Butterbur has clinical trials showing its effectiveness against some over the counter antihistamine medications. This is impressive as not too many other natural remedies have this sort of data to draw upon.
Although Quercetin does not have the scientific research that Butterbur does, it does have lots of anecdotal and clinical experience being used for seasonal allergies or allergic rhinitis. Its main purpose for being on this list is due to the fact it has been shown in vitro to prevent the release of histamine which is implicated in allergic symptoms such as sneezing and itching.
3. EGCG – Green Tea Extract
Surprisingly, Green Tea Extract jumps the list ahead of another staple allergy remedy in Vitamin C. Green Tea Extract has been shown to block the production of IgE and histamine (in vitro). What makes this potential mechanism unique and intriguing is that, in order for a cell to release histamine it needs this immunoglobulin (IgE) to bind the cell to signal to the cell to release histamine. If Green Tea Extract can work on blocking the signal before the cell knows to release histamine, it actually works one step before Quercetin or Vitamin C in helping with allergies.
4. Vitamin C
Vitamin C is thought to work similarly to Quercetin in terms of preventing mast cells from secreting histamine and ‘stabilizing’ them. It also is thought to help breakdown histamine once it has been secreted from a cell and cause allergic symptoms. According to the Journal “American College of Nutrition” – High-Dose vitamin C therapy (1-2g/day) may help asthma and allergies, however, it takes a few days of supplementation before Vitamin C starts to lower histamine levels.
5. Vitamin D
Since this list is more about controlling allergies once they have started, Vitamin D falls lower on the list. If the list was for preventing or preparing for allergy season, Vitamin D, probiotics (specific strains is a must) and Omega-3s would have been high on the list. Vitamin D makes the list at #5 as studies have shown it is important in terms of the development of immune tolerance and has been shown higher Vitamin D intake by pregnant mothers reduces the asthma risk as much as 40% in children aged three to five. These studies have shown results as well in allergic disease development. Vitamin D also makes the list as being here in Canada, it has a much larger necessity for ongoing supplementation to prevent deficiency.
Disclaimer: Please consult your health care provider regarding Vitamin D supplementation over the long term.