Healthy adults under age 75 are unlikely to benefit from taking more than the recommended daily intake of vitamin D, according to a new clinical practice guideline from the Endocrine Society.
The guidelines also state that regular testing of vitamin D levels is “unnecessary” for these people.
The recommended daily intake of vitamin D is 600 IU for people between the ages of 1 and 70. For people over 70, the recommended intake is 800 IU.
The guidelines recommend higher vitamin D intakes beyond the daily allowance recommended by the Institute of Medicine (IOM) for certain groups, including children, pregnant women, adults aged 75 years and older, and those with high-risk prediabetes.
Vitamin D has been linked to a variety of health conditions, but the effectiveness of supplementation in reducing disease risk and optimal blood levels for health have been debated.
The guidelines aim to clarify vitamin D use and testing in healthy individuals who do not require vitamin D treatment, based on clinical trials.
The guideline, published online and scheduled to be published in the August 2024 issue of The Journal of Clinical Endocrinology & Metabolism (JCEM), addresses the need for vitamin D for disease prevention in generally healthy populations.
“The goal was to determine the vitamin D requirements of healthy populations who have no conditions that impair vitamin D absorption or action,” said Dr. Marie DeMay of Harvard Medical School and Massachusetts General Hospital, who chaired the committee.
“People over 75, pregnant women, adults with prediabetes, and children and adolescents may benefit from higher doses, but we do not recommend routine vitamin D testing for any group,” Dr. DeMay added.
Key recommendations of the study
- Healthy adults under 75 years of age: Avoid taking vitamin D supplements in excess of the IOM recommended dose.
- Children and Adolescents (18 years and younger): High doses may help prevent nutritional rickets and respiratory infections.
- People 75 and older: Taking a higher dose may lower risk of death.
- Pregnant women: Higher doses may reduce the risk of preeclampsia, intrauterine mortality, preterm birth, and neonatal mortality.
- People with prediabetes: Higher doses may slow the progression to diabetes.
- Adults 50 years and older with an indication for vitamin D: Prefer low-dose vitamin D taken daily over high-dose vitamin D taken daily.
- Routine testing: Due to insufficient evidence regarding result-specific benefits, routine testing of 25-hydroxyvitamin D levels is not recommended, including in darker-skinned and obese individuals.
Despite increased research into the role of vitamin D in health over the past decade, the committee noted that existing evidence has limitations.
Many large clinical trials were not designed to evaluate multiple reported outcomes, and the populations studied often had initially adequate vitamin D levels, so the committee was unable to establish specific blood level thresholds for adequacy or disease prevention.
The guidelines were developed using rigorous methods to ensure that there were no conflicts of interest between the panel leaders and the majority of writing group members who had no conflicts of interest.
The Endocrine Society’s Clinical Practice Guidelines Program provides evidence-based recommendations for the diagnosis, treatment, and management of endocrine-related disorders, and all guidelines are fully funded by the Society.
