Most shark attacks occur less than 100 feet from the shore. More people are killed by bee stings and lightning than by shark attacks. Worldwide about 30 people die each year from shark attacks, which means a person has a one in 300 million chance of being killed by a shark. A shark attack most often occurs when a shark mistakes a person for a seal or other animal.
The new 2010 recommended daily allowance (RDA) is 600 IU for those 1-70 years of age and pregnant or breastfeeding women, and 800 IU for those over 71 years of age. An adequate blood level of vitamin D is 20 nanograms per milliliter, which can be achieved through daily skin exposure to sunlight.
Postmenopausal women need to be mindful of their daily intake, too: The IOM suggests that those who take supplements may actually be getting too much calcium, putting them at risk for kidney stones. The IOM recommends the following for daily vitamin D intake: Women and men 51 to 70: 600 IU.