As the moment of truth with your bathing suit inches closer, you might be cursing your sweet tooth for the belly bulge you can't seem to shed. But it could be what you're not eating that's actually responsible.

6 Nutrients for Faster Weight Loss
 

A 2000 study reported in the Archives of Internal Medicine reports that 77 percent of Americans are vitamin-D deficient. Numerous studies have shown D's crucial role in strengthening bones, fighting depression, and boosting immunity, but now, after decades of research and thousands of studies, experts may have finally proven that missing out on that one little letter could be a major factor in pushing the number on your scale higher and higher.

The Best Times to Eat for Weight Loss
 

Heavy D, Slimmer You
Unlike most vitamins, D can be manufactured by your body, provided you're exposed to sunlight. But sunscreen-a must for preventing wrinkles and, of course, cancer-reduces your skin's ability to make D by 90 to 99 percent, depending on the level of SPF thoroughness of application.