Much of the American population (including a majority of pregnant women) are deficient in vitamin D. Odds are good that you are too. A big contributing factor

Much of the American population (including a majority of pregnant women) are deficient in vitamin D. Odds are good that you are too. A big contributing factor is insufficient exposure to sunlight. Some have speculated that seasonal winter flu season is attributable to vitamin D levels. http://www.usatoday.com/news/health/2008-07-13-vitamin-d-tests_N.htm http://www.usatoday.com/news/health/2008-07-13-vitamin-d-tes...