New Guideline Suggests Some People Should Take More Vitamin D

Endocrine Society experts say that specific populations may benefit from taking more vitamin D than current guidelines recommend, while others may not need higher doses.

Vitamin D, AKA the "sunshine" vitamin, is a fat-soluble vitamin obtained from sun exposure, foods, and supplements. While research suggests that vitamin D supplements may lower the risk of dementia, heart attack, and specific types of cancer, scientists are still uncertain about how much vitamin D people need for optimal health.

Now, a new Endocrine Society Clinical Practice Guideline published on June 3 suggests that the amount of vitamin D a person needs depends on their situation. Moreover, many individuals don't need more than the recommended amounts and may not require testing for vitamin D levels.

How much vitamin D does a person really need?

A panel of experts from the Endocrine Society reviewed volumes of research to determine whether taking vitamin D supplements could lower the risk of disease in specific populations — particularly people with no indication of a vitamin D deficiency.

After analyzing the findings, the panel concluded that healthy adults under the age of 75 do not require testing for vitamin D levels and are unlikely to benefit from taking more than the U.S. Institute of Medicine's (IOM) recommended daily allowance of 600 IU for people ages one to 70 years and 800 IU for those older than 70.

In a press release, the panel's chair, Marie Demay, M.D., from Harvard Medical School and Massachusetts General Hospital, said, "Healthy populations who may benefit from higher dose vitamin D supplements are those 75 and older, pregnant people, adults with prediabetes, and children and adolescents 18 and younger, but we do not recommend routine testing for vitamin D levels in any of these groups."

Guideline recommendations

According to the Endocrine Society, children and teens aged 18 and under should take more vitamin D to prevent rickets and lower the risk of respiratory infections. Clinical trials included in the analysis used vitamin D dosages from 300 to 2,000 IU per day, with an average daily dose of about 1,200 IU.

Moreover, higher vitamin D intake among pregnant individuals may help reduce the risk of pregnancy complications such as preeclampsia and preterm birth. After reviewing the research, the panel found that vitamin D dosages in trials involving pregnant individuals ranged from 600 to 5,000 IU per day, with doses averaging around 2,500 IU daily.

Additionally, taking more vitamin D may lower mortality risk in adults 75 and older. Vitamin D doses noted in the reviewed clinical trials were 400 to 3,333 IU per day, with an average daily intake of 900 IU.

The panel also suggests that people with prediabetes who take more than the recommended daily allowance of vitamin D may reduce their risk of developing diabetes. For participants in clinical trials, vitamin D dosages ranged from 842 to 7,543 IU, with average doses of approximately 3,500 IU per day.

The experts only noted vitamin D dosages used in the studies and could not determine the optimal dose required for disease prevention. However, they did suggest that taking daily, lower-dose vitamin D is better than taking a higher dose intermittently.

In addition, based on available evidence, the panel does not recommend routine testing for 25-hydroxyvitamin D levels for any of the groups studied, including people with obesity or darker skin.

Vitamin D research is still lacking

Though the review of research showed that some people may benefit from taking higher doses of vitamin D, the limitations of available evidence and inconsistent results made it challenging for the panel to finalize its recommendations.

Therefore, the Endocrine Society panel says that more research is needed to clarify the potential benefits and harms of taking higher doses of the "sunshine" vitamin and warns that this new guideline should not be considered an all-encompassing supplementation approach.