Allergy reduced by vitamin D      
There are at least 5 reasons to believe that vitamin D can reduce pollen allergies.
1) Latitude. It has been known for a long time that there are more allergies the further that one if from the equator. There has been a lot of research for serious diseases such as MS and some cancers which show a strong (3 to 1) variation in occurrence with latitude.  It appears that in all cases that the variation is due to the variation in UV-B which produces vitamin D.
2) Spring.  Many pollen allergies are worse in the spring. This is the time of the year that the body has the least amount of stored vitamin D.  The body stores are all depleted by the spring, and are not yet recharged the summer sun.
3) Fewer allergies on farms. At first this seams counter-intuitive.However, people on farms tend to be out of doors more, and so tend to get more UVB which produces vitamin D
4) Asthma is helped with Vitamin D (see in clipping below) 
5) High altitude, fewer allergies.  The clipping below states that the fewer allergies is due to having fewer allergens.  I believe, however, that the reduced allergies may be due to the increase in UVB at increased altitude. The UBV/altitude relationship is so well understood that there is even an equation for amount of UVB increase for every 300 meters gain in altitude. Some portions of Colorado, for example, gets more UVB than the rest of the US with the exception of southern Florida and the high Sierras of California

I would recommend taking 5,000 IU of vitamin D daily until about June, at which point the vitamin D from the sun starts to kick in and you can consider dropping back to 2,000 IU. 
About 0.1% of the population have problems with vitamin D, so I would recommend checking your reaction to it first – say by having only 5,000 IU for the first week. 
Many doctors prescribe a large starter dose to charge up the body initially for those who are very deficient (elderly, dark skin, and a few other at-risk groups). The large dose prescribed is typically 50,000 IU, but some doctors prescribe 300,000 IU and more. A steady 5,000 IU per day will re-charge the body to summer levels in about 2 months.  An initial high dose will charge the body up in about 1 month.
The following I clipped from the web on Feb 17 2010
_____________________________________________________________________
From Allergy news of 2009? http://www.pollen.com/newsfeed.asp?file=100128newsfeed_daily_t.dat 
Too Little Vitamin D May Worsen Asthma
THURSDAY, Jan. 28 (HealthDay News) -- People with asthma who have low levels of vitamin D fare worse than those with high levels of the "sunshine" vitamin, a new study finds.
Researchers found that asthmatics with high vitamin D levels have better lung function and respond better to treatment than asthmatics with low vitamin D levels do.
"Our findings suggest that low vitamin D levels are associated with worse asthma," said lead researcher Dr. E. Rand Sutherland, from the division of pulmonary and critical care medicine at National Jewish Health in Denver.
In addition, vitamin D levels predict how well "somebody is going to respond to steroidal asthma medications," he said. "It may be that vitamin D is acting as a modifier of the immune system or a modifier of steroid response in ways that are relevant to people with asthma."
The report is published in the Jan. 28 online edition of the American Journal of Respiratory and Critical Care Medicine.
For the study, Sutherland's team took the vitamin D levels of 54 asthmatics and assessed lung function, airway hyper-responsiveness, which is the prevalence of airway constriction, and response to steroid treatment.
People with low levels of vitamin D in their blood did worse on the tests that evaluated lung function and airway hyper-responsiveness, the researchers found.
In those with vitamin levels below 30 nanograms per milliliter (ng/ml), airway hyper-responsiveness almost doubled, compared to those with more D in their blood.
Low vitamin D levels were also associated with a worse response to steroid therapy and increased production of the pro-inflammatory cytokine, TNF-alpha. This raises the possibility that low vitamin D levels are tied to increased inflammation of the airways.
The heaviest participants had the lowest levels of vitamin D, the study noted. Asthma is associated with obesity, and this (lack of vitamin D) may be a factor linking the two conditions, Sutherland said.
"There is a potential that restoring normal vitamin D levels in people with asthma may help improve their asthma," Sutherland said.
But whether vitamin D supplements will help asthmatics isn't known, he added.
Current recommendations for vitamin D supplements for adults is 400 IU to 600 IU, depending on age, according to the U.S. National Institutes of Health.
"There is likely little harm in adhering to those guidelines," Sutherland said.
The Institute of Medicine is currently evaluating these levels and expects to announce new guidelines in May.
Sunlight, fatty fish and fish oils are also sources of vitamin D.
Dr. Michael F. Holick, director of the Vitamin D, Skin and Bone Research Laboratory at Boston University School of Medicine, called this "a very nice study that confirms previous observations that vitamin D enhances lung function."
"It is also known that glucocorticoids [steroids] increase the destruction of vitamin D, thus making patients with asthma at higher risk for vitamin D deficiency, which in turn decreases lung function and makes their disease worse," he said.
Holick thinks most people, asthmatic or not, get too little D and should take supplements.
"It's pretty clear that you need a minimum of 1,400 and up to 2,000 IU a day, and if you are obese, you probably need at least one and a half to two times as much, because the fat sequesters the vitamin D," Holick said. "We now recognize that you can take up to 10,000 IUs a day and not worry about any untoward toxicity.”
________________________________________________________________
Clipped from http://paulkrotoblog.com/archives/tag/vitamin-d 
Lack of Vitamin D and Your Immune System
Lack of vitamin D can greatly weaken your immune system which can leave you vulnerable to infections and allergies that cause even more fatigue.
To understand why a weakened immune system can cause allergies, you have to understand what an allergy is.  An allergy is when the immune system attacks something it should ignore. The immune system should ignore pollen, but instead it attacks it.  Have you ever noticed how difficult it is to tell the difference between a cold and an allergy?  When you get a cold, a virus invades the throat and sinuses.  The body then tries to make these places less hospitable to the virus by flushing out the area with mucous.  When you have a pollen allergy, pollen gets into these areas.  The immune system should leave it alone, but because it is weakened and not functioning properly it attacks the pollen the same way it attacks a virus.
**********************************************************************
Not much vitamin D in Bee Pollen
Clipped from: http://www.appliedhealth.com/nutri/page6991.php 
The levels of vitamin D, vitamin E and vitamin K in pollen were assayed. Fatty material from bee-gathered pollens contain between 0.2 to 0.6 IU's of vitamin D per gram of pollen fat. The pollen fat also contained 0.32 mg per gram of vitamin E. Vitamin K has not been found in mixed pollens, although bee bread, which is fermented bee pollen, has vitamin K activity.
__________________________________________
Pediatr Allergy Immunol. 2006 Nov;17(7):477-83.
The vitamin D slant on allergy.  Wjst M.   Abstract
Oral vitamin D supplementation has been introduced into modern medicine to prevent rickets without the knowledge that this may have profound immunological consequences. The main vitamin D metabolite calcitriol suppresses dendritic cell maturation and consecutive Th(1) cell development, which has independently described as a key mechanism of allergy development. Animal studies and epidemiological surveys now provide a first link of early vitamin D supplementation and later allergy where several vitamin D regulated genes seem to be involved. A randomized clinical trial of vitamin D supplementation could be a further step to follow up the vitamin hypothesis.
PMID: 17014620 [PubMed - indexed for MEDLINE]
__________________________________________
Clipped from http://www.achooallergy.com/sunlight-allergies-asthma.asp 
Sunlight & Allergic Disease
Last year, a study in the Journal of Allergy and Clinical Immunology found that southern states have the fewest Epipen prescriptions, while New England states have the most. (The Epipen contains injectable epinephrine and is necessary for people who have severe, life-threatening allergies.) Researchers hypothesize that since southern states have more year-round sunlight, people in those states have a lower incidence of allergic disease because of higher Vitamin D levels.
In 2006, Australian researchers found that exposure to sunlight for 15 to 30 minutes before exposure to allergens significantly reduces the development of asthma-like symptoms! (So if you have a child with asthma, don't let him or her sit indoors and play video games all summer – even if the game system is a fitness-conscious Wii!)
At the 2008 annual meeting of the American Academy of Allergy, Asthma and Immunology (AAAAI), Dr. Matthias Wjst explained that dietary sources of vitamin D are not ideal.
It is best to get your vitamin D from natural sunlight exposure, as opposed to dietary supplements.
In fact, dietary supplementation of vitamin D may be related to the increase in allergies and asthma in recent years.
Early-life vitamin D3 dietary supplementation has been linked to asthma Early-life vitamin D3 dietary supplementation has been linked to asthma. Dr. Wjst also pointed out that inhabitants of the islands of Tristan da Cunha have a very high incidence of allergies and asthma - and they consume a very high amount of dietary vitamin D from sea bass.
Dr. Wjst proposed that oral vitamin D supplementation could be a not-so-visible component of the hygiene hypothesis. The "hygiene hypothesis" is a hot topic among allergists; it suggests that the prevalence of allergic diseases in modern, developed societies is related to our overly hygienic lives. For example, kids who grow up on farms usually have lower rates of allergies and asthma. {and they are probably getting much more UVB/vitamin D by being on a farm} However, if a child stays indoors in a sterile environment all the time, then his immune system is never challenged and never has a chance to "learn" what it should attack. Thus, the immune system overreacts to substances like pollen.
Dr. Wjst suggested that perhaps oral vitamin D supplementation early in life leads to fewer infections and therefore more allergies; this is another way of looking at the hygiene hypothesis.
Dr. Margherita Cantorna, PhD, also presented evidence for the role of vitamin D in asthma and autoimmune diseases. Vitamin D deficiency exacerbates autoimmune diseases like multiple sclerosis, lupus, arthritis, type I diabetes, and inflammatory bowel disease. Also, inflammatory bowel disease is much more prevalent in urban areas, northern areas, and developed countries. Vitamin D seems to normalize T-cell function in the immune system, says Dr. Cantora.
So... It appears that too much vitamin D in the diet may increase the incidence of allergic disease; however, too little vitamin D can make allergic diseases worse.
Here's the key point: People generally don't get hyper-doses of vitamin D by spending time in the sun; however, it's easy to get hyper-doses of vitamin D through oral supplementation. That's why it's best to get your Vitamin D through sunlight rather than supplements.
Dr. Thomas A.E. Platts-Mills, former President of the AAAAI and one of the world's preeminent allergy researchers, has also alluded to the connection between Vitamin D and allergies.
Dr. Platts-Mills believes that the hygiene hypothesis does not offer a full explanation. He thinks that the rise in allergies and asthma is due to the fact that we have essentially become an indoor species: "Yes, you need cleanliness in order to get allergy, but the rise in asthma from 1960 onward, which was occurring among allergic patients, is much more likely to be due to the major change in lifestyle that occurred then, which is that we moved indoors and have essentially become an indoor species. In the 1950s, children would spend three hours a day outdoors playing. From about 1960 onwards, that's progressively decreased so that now it's unusual for children to go outdoors. The outdoor exposure could be beneficial because it allows the children to open up their lungs and exercise their lungs; it could be beneficial because they don't get so fat; it could be beneficial because their environment is better; or even, as has recently been suggested, because they get more exposure to the sun and therefore aren't vitamin D deficient."
So... If you're the parent of an allergic or asthmatic child, make sure that your child plays outdoors and gets plenty of sunlight this summer! (And don't forget to expose yourself to the sunlight, too.)
__________________________________________
http://www.abc.net.au/news/stories/2009/12/11/2769736.htm
ABC News Australia  Sun exposure linked to allergies By Madeleine Genner for PM   Dec 11, 2009 
In recent years the number of children with food allergies has skyrocketed and now researchers say there could be a link between allergies and where you live.
A new study has found that Australians living in northern latitudes are less likely to suffer from allergies. Researchers say their findings suggest a link between the allergies and sun exposure.
Australia has one of the highest rates of food allergies in the developed world.
Currently about 5 per cent of children develop an allergy by the time they start school.
Dr Raymond Mullins, an allergy specialist attached to both the ANU Medical School and Health Sciences at the University of Canberra, says allergies have become much more common in the past few years
"I'm not talking about hyperactive kids after too much red cordial. This is well-defined immune allergic reactions to peanut, egg, milk and so on," he said.
"If you don't have a reason why it's happening, you have no way of intervening to reduce the risk.
"So trying to examine why some people have food allergy and other people do not might give you a clue about how to intervene and reduce the risk long-term."
Dr Mullins now believes he has found part of the solution. In a paper published today in a number of medical journals, he describes how he has found a link between food allergies and latitude.
"What we've looked at in this study is three different markers of food allergy risk, mainly in children," he said.
"One is EpiPen adrenaline prescriptions, which you give in people who have dangerous reactions.
"The second is in infant baby formula that you prescribe to people who have multiple food allergies, so young babies. And the third is how often hospital admissions for dangerous allergic reactions or anaphylaxis occurred.
"So what we found was that all of those three were much more common in the southern parts of Australia than in the north and sometimes six-fold, sometimes 20-fold difference in south versus north.
"Now there are many reasons why differences might occur. So we've looked at things like the income, employment, education level, where people were born in those 60 different regions where we examined frequency.
"And the only thing that came out was latitude."
Dr Mullins says a number of studies have shown a similar link in regions of the US. This study could help prove the connection is found all over the world.
The Murdoch Children's Research Institute's Associate Professor Katie Allen says the research may provide answers to the worldwide food allergy epidemic.
"We absolutely are finding a very high prevalence of food allergy in southern states and those findings support that there is potentially this sort of north, south region variation," she said.
"And there is this very big interest in what could be driving the epidemic food allergy that's happening around the world, but particularly in developed countries."
Vitamin D link
Dr Mullins says that any connection between latitude and food allergies suggests that allergies are linked with a deficiency of vitamin D.
Now more testing needs to be done to check if children who have food allergies also suffer from a vitamin D deficiency.
"We know that vitamin D plays an important part in bone and muscle health. If you don't have adequate levels in childhood you get rickets and deformed bones," Dr Mullins said.
"In adults you get soft bones and more frequent broken bones and fractures.
"But there's recent evidence that low vitamin D may also play a role in other conditions like multiple sclerosis, diabetes, cancer, that sort of thing and in the last couple of things allergic diseases as well."
But Dr Mullins cautions against over interpreting the study. While some Australians do not get enough vitamin D he says the research is not a reason to abandon the sun safe message.