There are two sides to every argument, so the saying goes, and usually the truth lies somewhere in between.

Fortunately, you don't have to takes sides in the debate about whether D-2 and D-3 are vitamins or hormones. Either way, they deliver nothing but good health to folks who get enough every day.

You see, D-2 and D-3 (they have similar actions in your body) function as vitamins by helping your body achieve normal growth and development.

As hormones, they work to regulate calcium absorption, immune-system functioning and bone health. But it doesn't stop there.

New findings indicate that guys with erectile dysfunction have significantly low vitamin D levels, and the more severe their dysfunction the greater the deficiency.

Scientists also have found that women with the highest levels of D (above 30ng/mL) have a pregnancy rate of 30 percent from in vitro fertilization; women who are deficient (below 20ng/mL) only have a 21 percent success rate.

Achieving a healthy level of vitamin D-2/3 is cheaper and better for you than taking ED meds or going through multiple in-vitro routines.

So, get a blood test to check your levels. Take a 1,000 IU D-3 supplement daily until you get results - then take what your doc recommends (it's hard to get enough from what you eat).

Plus, get outside (with SPF 30 sunscreen) for 30 minutes a day and eat vitamin-D-rich foods such as salmon, D-3-fortified whole-grain cereals and nonfat dairy or nut milks and white mushrooms. D-licious.

© 2014 Michael Roizen, M.D. and Mehmet Oz, M.D.
Distributed by King Features Syndicate, Inc.