Getting Enough Vitamin D?

When you’re not ingesting enough vitamin D with your food, supplements can help

By Deborah Jeanne Sergeant

In addition to your summertime tan, your vitamin D stores have long since disappeared. While excessive sun is not so good for your skin, in moderation, it makes the body generate vitamin D, a pre-hormone that modulates many important bodily systems, including the immune system.

Why is D important?

In addition to regulating functions of the body, vitamin D also helps the body absorb many of its nutrients, such as calcium, magnesium and phosphate.

“They are finding more and more ways the body uses vitamin D,” said Julie Mellen registered dietitian, certified diabetes care and education specialist at SUNY Upstate Medical University.

It reduces inflammation. Low levels of vitamin D have been linked to cognitive decline and osteoporosis.

Who needs more vitamin D?

Nearly everyone in North America. The sun is not intense enough from about October through May to trigger production of vitamin D.

“A lot of people can’t meet their needs for vitamin D,” Mellen said.

People who are homebound, work indoors or cannot expose their skin to sunlight because of other health conditions may be at especially higher risk for vitamin D deficiency year-round.

Where can we get vitamin D?

Primarily, it’s through the UVB radiation in the sun. While too much exposure can cause skin cancer, 20 minutes’ exposure a few times a week suffices for generating vitamin D.

The few foods that offer vitamin D provide so little that most people could not eat enough of them to supply all of their needed vitamin D.

“Supplementation is the primary source, unless you’re big into salmon, sunlight, tuna and sardines,” Mellen said.

She added that commercially processed milk and other fortified products such as most boxed breakfast cereals contain vitamin D. Milk processed by an on-farm creamery may not have vitamin D added. Eggs contain vitamin D, but the amount offered by eggs depends upon the chicken’s diet. Mushrooms contain a small amount of vitamin D.

How much D do we need?

As a fat-soluble nutrient, vitamin D is stored by the body if it gets too much. Vitamin D generated through sunlight exposure does not cause toxicity. However, supplemented D can.

Most people older than 70 need more vitamin D than younger people because of malabsorption.

The amount of vitamin D one needs varies depending not only on age but also other health concerns.

“Get a baseline through bloodwork,” Mellen said. “If you’re deficient, you’d want to supplement. The sources aren’t always readily available through diet.”

Laurel Sterling, registered dietitian and nutritionist and educator for Carlson Laboratories, said that most people should take a higher dose of vitamin D supplements from September through May.

“Ask to get your levels checked,” she said. “Doctors aren’t always checking this. There are at-home test kits available. We have them at my company and there are others out there. They cost $50 or so. You prick your finger and mail it in.”

She added that it may take two to three months to raise vitamin D levels to sufficient levels.

So Why Do I Have Vitamin D Pills?

Unfortunately, doctors do not prescribe a vacation to a sun-soaked island for their patients deficient in vitamin D. Instead, it’s a supplement providing 50,000 international units (IUs) of vitamin D per dose. Over-the-counter vitamin D provides at the most 10,000 IUs.

Vitamin D helps the body absorb nutrients. Vitamin D deficiency can cause rickets in children and in adults, hypoparathyroidism, osteomalacia, hypocalcemia, or bone diseases, which is why a prescription is sometimes necessary.