While I have been spending a lot of time around sick people in the last few days, I have heard a lot of discussion about taking the H1N1 Flu Vaccine, or not. I don't have any advice to offer, but a few other thoughts come to mind.
In some recent blood tests I had, my doctor also ran my vitamin D levels. It is commonly believed that we make enough vitamin D if we get a few minutes of sunshine three or four days a week. At the time of my blood tests, I had been working out in the garden almost every day for several hours all summer, unless it was raining. I wear a sleeveless tee and shorts so I have good skin exposure to the sunlight, and I drink lots of milk, which is labeled as having Vitamin D added.
With all that exposure, my level of D was still deficient. Not merely low, but deficient. So, I've been reading up on vitamin D. Many factors affect the body's ability to absorb D, plus the receptors in the skin diminish greatly with age. Surprisingly, as many as 40% of older people living somewhere like sunny Florida are deficient in vitamin D. Other factors also affect the body's ability to absorb vitamin D such as some diseases, taking a lot of medications, and some interactions in the digestive system. (I don't think we know enough about the interactions of everything that affects our metabolic function.)
Vitamin D is found only in small amounts in a very few fatty foods like sardines, herring and mackerel. I believe the amount added to milk is probably just enough to make the label legal. Diseases like osteoporosis, or even just having aging kidneys, will affect vitamin D levels.
The role of vitamin D in the body is to regulate the use of calcium and phosphorus (think strong bones), and to enhance immunity. It is also necessary for thyroid function and blood clotting. Studies are showing vitamin D is a good preventative measure for breast and colon cancers. I'd say that's because of how vitamin D affects the immune system.
Fortunately, vitamin D is easy to synthesize, and inexpensive to purchase. My doctor has me taking 1,000 units of D3 daily, and said if I get a cold, or the flu I could increase it to 5-10,000 units daily.
Vitamin D is one of the fat (lipid) soluble vitamins, which means the body may store any it doesn't need, and although very few cases of any vitamin toxicity have ever been reported it is possible with mega-doses. The water-soluble vitamins (we excrete any excess) are the B vitamins and vitamin C. Vitamin A in the form of beta-carotene is also water-soluble.
I am not recommending you take vitamin D, only saying I take it and why. I also take an immune-building homeopathic remedy, wash my hands a lot, and carry wet-wipes when I go anywhere.
The best anyone can do is do their own homework before making a decision about anything you put in the body.