Trying to figure out which vitamins to take and how much of each can be overwhelming, but some in the medical community say if you only take one, make it Vitamin D.

Researchers are learning more and more about the benefits of Vitamin D. They are now linking it to everything from your mood to your immune system to bone health, heart disease, even the prevention of dementia and some cancers.

So, why are we talking about it now? And why aren’t some of us getting enough?

Dr. Kathleen Ververeli, an allergist and immunologist with Center for Allergy and Asthma Care in Allentown, said she talks about Vitamin D with her patients all the time.

“Vitamin D everybody thinks is just a vitamin,” Ververeli said. “But it’s actually a hormone and there’s recpetors in our body all over our body in our brain, in our lung in our skin, on our immune cells.”

It’s been called the sunshine vitamin because it’s best produced in your skin in response to sunlight. And that’s part of the problem.

“The problem is that only works in this area from April to October,” Ververeli said. “And we’re indoors, everybody lives indoors, we work indoors and when we do go out in the summer what do we do? We wear sunblock.”

Ververeli sees lots of asthma, allergies, eczema and auto immune disease in her busy practice. She tells her patients to take vitamin D.

“What has happened over the last two decades, maybe more, is we have seen decreasing levels of vitamin D in patients,” she said. “And we’ve seen a lot of increases in these diseases: allergic disease, auto-immune disease, infectious disease and malignancies.”

You can get Vitamin D in some foods like:

  • salmon
  • sardines
  • egg yolk
  • shrimp
  • milk
  • cereal
  • yogurt
  • and orange juice.

But Ververeli says that’s not enough. She suggests:

  • Children under 4: take 1,000 IU
  • Children 4-8: take 2,000 IU
  • Over 8: Take 4,000 IU.

“It helps fight infections, it helps with that it’s important to balance the immune system,” she said. “So if you have a normal level, it helps to decrease allergy disease and auto immune disease.”

The doctor reminds patients to take a vitamin D tablet with some kind of fat.

“It’s a fat soluble vitamin, so if you’re taking it in a tablet form you should be eating it with a fatty meal,” Ververeli said

Or she says you can take an oil with Vitamin D in it.

Researchers say adults over 50 don’t make as much vitamin D in response to sun exposure, which increases their chances of developing bone abnormalities like osteoporosis. Doctors say you can get your levels checked with a simple blood test.