It is worth it to point out that Vitamin D has been shown to prevent colds...but the "recommended" dose unfortunately still leaves people deficient.
A nutritionist recommended I take at least 5000IU a day (with regular blood tests to confirm I wasn't going over the limit.) My blood test level started out at 18 (extremely low, despite the fact that I lived in San Diego at the time) and is now a more respectable mid-50s.
Anecdotally, I can say it's made such a huge difference in me getting less sick on a regular basis (and is SO cheap) that I've been recommending it to pretty much everyone I know.
I've also become a huge fan of NOT wearing sunscreen, especially if you're going to be out in the sun for less than an hour. With proper Vitamin D levels, you actually burn less. Try it for yourself and see--it's been a massive difference in my life.
Vitamin D I use (Only $8 for 4 month's worth! Disclaimer--Amazon affiliate link, but it is actually what I use) http://amzn.to/zJYS1X
Important information is missing here, you age, gender, and race. (I am not asking you to provide this information, I'm suggesting people see medical advise before arbitrarily starting a supplement)
Your skin's pigment density is an important aspect of how you handle sunlight. Your ability to process these chemicals is a function of all three, lifestyle, and other health factors.
A nutritionist recommended I take at least 5000IU a day (with regular blood tests to confirm I wasn't going over the limit.) My blood test level started out at 18 (extremely low, despite the fact that I lived in San Diego at the time) and is now a more respectable mid-50s.
Most Americans are chronically Vitamin D-deficient (sources: http://www.scientificamerican.com/article.cfm?id=vitamin-d-d... and http://planetgreen.discovery.com/food-health/vitamin-d-defic...) and at this point, it's pretty much safe to assume that you're not getting enough of it and to consider taking a 2000-5000IU daily supplement.
Anecdotally, I can say it's made such a huge difference in me getting less sick on a regular basis (and is SO cheap) that I've been recommending it to pretty much everyone I know.
I've also become a huge fan of NOT wearing sunscreen, especially if you're going to be out in the sun for less than an hour. With proper Vitamin D levels, you actually burn less. Try it for yourself and see--it's been a massive difference in my life.
Vitamin D I use (Only $8 for 4 month's worth! Disclaimer--Amazon affiliate link, but it is actually what I use) http://amzn.to/zJYS1X