Should You Get Tested for Vitamin D?

Experts say it’s difficult to get too much vitamin D. TARIK KIZILKAYA/Getty Images

The U.S. Preventive Services Task Force said there isn’t sufficient evidence to recommend for or against screening most people for vitamin D defic…

Experts say it's difficult to get too much vitamin D. TARIK KIZILKAYA/Getty Images
  • The U.S. Preventive Services Task Force said there isn’t sufficient evidence to recommend for or against screening most people for vitamin D deficiency.
  • Experts say that vitamin D is essential for health and they’re surprised at the task force’s decision.
  • Experts caution that while vitamin D overdosing is difficult and rare, too little in our bodies is associated with sometimes severe illness.

The U.S. Preventive Services Task Force (USPSTF) has determined there isn’t sufficient evidence to recommend for or against testing for vitamin D deficiency in adults, according to a recent recommendation statement.

However, the USPSTF emphasized that this recommendation does not apply to people who are pregnant, anyone with signs and symptoms of vitamin D deficiency (like muscle weakness or bone pain), and people with conditions that require vitamin D treatment.

But does this mean you shouldn’t bother to be tested at all?

Experts point out importance of vitamin D for health

Rajsree Nambudripad, MD, integrative medicine specialist with Providence St. Jude Medical Center in Orange County, California said she screens all patients with a 25-hydroxy vitamin D test at their initial consultation. 

“I consider vitamin D to be one of the most essential vitamins in the body,” she said. “I find that over 50 percent of my patients are low at their initial consultation.”

She added that this is easily correctable with supplementation.

According to Nambudripad, multiple sclerosis is associated with low vitamin D levels, and having low vitamin D can cause many vague symptoms that range from fatigue and low mood to body aches.

“Severe vitamin D deficiency can cause osteoporosis, brittle bones, and fractures. In children, severe vitamin D deficiency can cause rickets, which is a softening or weakening of bones,” she said.

Who is most at risk for deficiency?

Nambudripad said people at risk for deficiency include those who work indoors or anyone who lives in the northern latitudes (due to less sunlight during winter).

She also pointed out that if you're going out midday but wearing sunblock on all exposed skin, you still may have a deficiency.

“You may be at higher risk of low vitamin D since we get some vitamin D from sunlight. Sunscreen also inhibits the formation of vitamin D from exposure to sunlight,” she explained.

But that doesn't mean you should avoid sun sunscreen. Instead, you can talk with your physician about the right diet or supplements if your vitamin D levels are low.

According to Nambudripad, other people at risk for deficiency include:

  • those who've had gastric bypass surgery
  • people with small intestine bacterial overgrowth
  • anyone with intestinal absorption problems like inflammatory bowel disease
  • people experiencing exocrine pancreatic insufficiency

If you’re following a restricted vegan diet, you might also have a higher risk of vitamin D deficiency, “since vitamin D is most commonly found in foods like dairy, eggs, and salmon,” she said.

USPSTF cautions against broad screening due to ‘uncertainty’

In their statement, the Task Force warned against potential harms of screening the general population for vitamin D deficiency.

“Screening may misclassify persons with a vitamin D deficiency because of the uncertainty about the cutoff for defining deficiency and the variability of available testing assays,” cautioned the USPSTF.

This may result in over or under-diagnosis — and people being inappropriately treated or not treated.

The Task Force also pointed out that one potential harm of treatment with vitamin D is toxicity.

“Vitamin D should be kept at an optimal level of 60–80 ng/mL,” explained Nambudripad. “If your level is greater than 100, you could be at higher risk of developing kidney stones since vitamin D increases your absorption of calcium.”

However, she said she rarely sees this, and even then, it’s usually in people taking over 10,000 IU of vitamin D daily. Standard over-the-counter vitamin D supplements come in 1,000 or 2,000 IU dosage.

Enriched foods and sun are essential for healthy vitamin D levels

Janine Souffront, RDN, supervisor and health educator at L.A. Care Health Plan, the largest publicly operated health plan in the United States, said dietary sources of vitamin D are limited and we rely on certain “enriched” foods to get what we need.

“Some fish does [contain vitamin D], such as salmon, herring, sardines, and canned tuna. Eggs from poultry fed vitamin D-enriched feed or raised outdoors (where they get sun) are high in vitamin D,” she said. “For the most part, we depend on foods enriched with vitamin D for our daily intake.”

Souffront listed milk, alternative milks, orange juice, oatmeal, and cereals as examples of vitamin D-enriched foods.

“In the past we relied on the sun for our vitamin D,” she said. “But because of our change in lifestyle, we do not get the recommended 20 minutes of almost daily mid-morning sun.”

She added that people are using less milk than in the past, meaning the best way to get vitamin D through diet is to make the foods she mentioned part of our regular diet.

Elena Gagliardi, clinical nutrition services manager at Santa Clara Valley Medical Center, emphasized the importance of meeting the Dietary Reference Intake (DRI) of 600 IU per day if you're 1–70 years old, or at least 800 IU per day if you're 71 years or older.

She also recommended getting about 5 to 30 minutes of outdoor sun exposure at least twice a day as another way to maintain sufficient vitamin D levels in your body.

“If you are unable to meet the requirement through food intake alone, talk to your doctor about supplementation of vitamin D3,” she advised.

Experts ‘surprised’ by USPSTF statement

“I'm surprised by the results and conclusions of the USPSTF statement,” said Nambudripad. “My practice has a preventive focus and my patients feel a significant improvement in their health when their vitamin D level is optimized.”

She added that she’s seen many patients with body aches, fatigue, and other issues improve as they’ve had their vitamin D levels optimized, along with addressing their diet and lifestyle. 

“For most patients, the blood test 25-hydroxyvitamin D is covered by their insurance,” she said. “So I like to be proactive and test, since it's something we can easily improve with supplementation.”

The bottom line

In a recent draft recommendation, the U.S. Preventive Services Task Force said there isn’t sufficient evidence to recommend for or against screening most people for vitamin D deficiency.

Experts say that vitamin D is essential for overall health and they're surprised at the decision.

While too much vitamin D is difficult to achieve and rare, too little is much more common and associated with sometimes severe illness.

For many people, a vitamin D test is covered by health insurance, and low levels can easily be improved with supplements.