#1 flat-belly vitamin hack

Research reveals an everyday nutrient that helps women like Gina Rose Sigman, 64, start melting ab fat 9.7 times faster

- ALLISON NEMETZ

Not long ago, scientists found that women with healthy vitamin D levels have slimmer (and therefore healthier) waists compared to millions of us with low D. Does that mean a supplement will loosen tight waistbands? It could! A slew of research links D supplements to a smaller middle. One even found extra D helps stimulate belly fat to burn up to 9.7 times faster than normal. Of course many of us already take D without noticeable results. To find out why, we turned to Seattle-area women's health expert Emi Hosoda, M.D., who says D was key to her own 100-pound weight loss. Here, Dr. Hosoda explains how D works and, more importantly, how we can absorb enough of the nutrient for it to work belly-shrinking magic.

Our bodies make vitamin D using sunlight and cholesterol in our skin, yet 80% of us still don’t have enough. Blame gloomy weather, sunscreen, aging, darker skin and certain gene variations; all are factors that inhibit D production. Dietary D options aren’t great either. D-fortified milk has a mere 100 IU per cup, eggs just 11 IU each; only fatty fish (about 350 IU per serving) makes a dent in the 600 to 800 IU of vitamin D experts advise us to get daily. The bottom line: “Unless you eat a lot of salmon and sardines and spend most of your time outdoors, you probably don’t have enough D,” says Dr. Hosoda.

How badly do you personally need more D? The only way to find out is to get tested. Insurance will often pay; alternatively, CVS makes a $40 home test kit. Any result from 20 ng/ml to 50 ng/ml is adequate, but Dr. Hosoda finds most women must be close to 50 ng/ml to feel and see a difference. As for those who already take a D supplement but still have stubborn belly fat, there’s a hack for that.

Here's your easy