Are you getting enough vitamin D? New guidelines turn conventional wisdom on its head, offering new recommendations that could impact your decisions about vitamin D intake and testing.

Known as the “sunshine vitamin,” vitamin D has become increasingly popular for its potential role in disease prevention. More than 18 percent of adults report taking vitamin D supplements, according to the Centers for Disease Control and Prevention.

However, the Endocrine Society’s 2024 guidelines now advise against routine vitamin D screening and routine supplementation for certain populations, including non-pregnant adults aged 19 to 74—a major shift from the 2011 guidelines, which recommended supplementation among all age groups.

The new guidelines sparked debate among some health care providers. Peter Osborne, a diplomate with the American Clinical Board of Nutrition and founder of Origins Healthcare, told The Epoch Times: “I disagree with the guidelines. Vitamin D is an essential nutrient that plays a pivotal role in multiple functions in the body. It is one of the most common deficiencies we see in the clinic.

“It makes absolutely no sense to try to deter the medical community away from routine screening. It’s such a simple thing to do.”

The new guidelines were developed by a panel of experts who analyzed data from randomized controlled trials that included individuals without overt indications of vitamin D deficiency.

Why Create New Guidelines?

“The Endocrine Society updates guidelines as needed based on accumulating evidence. The new guideline incorporates data from trials done since the publication of our 2011 guideline,” the Endocrine Society told The Epoch Times.

While the 2011 guidelines addressed the evaluation, treatment, and prevention of vitamin D deficiency, particularly for at-risk patients, the goal of the panel was to create guidelines for using vitamin D to reduce disease risk in generally healthy people who don’t have clear reasons to be treated for vitamin D deficiency or to have their vitamin D levels tested.

According to the Endocrine Society’s clinical practice guidelines, published in the Journal of Clinical Endocrinology & Metabolism in June, low levels of vitamin D are consistently associated with disorders such as autoimmune, cardiovascular, metabolic, musculoskeletal, and infectious disease. However, correlation does not necessarily mean causation.

“Although a causal link between serum 25(OH)D concentrations and many disorders has not been clearly established, these associations have led to widespread supplementation with vitamin D and increased laboratory testing for 25(OH)D in the general population,” the guidelines state.

“The balance between the benefits and risks of increasing vitamin D use is not clear, and the optimal vitamin D intake and the role of testing for 25(OH)D levels in disease prevention remain uncertain.”

Osborne takes issue with these conclusions and how they were reached. “There’s a tremendous amount of evidence, both in the literature but also clinically speaking. A lot of clinical evidence is never published so it doesn’t get used when they’re doing review studies or review papers like this one that was done by the Endocrine Society,” he said.

“From a clinical perspective, vitamin D is tremendously powerful in the tool belt of clinicians. When people come into my clinic, we see direct benefits from the use of vitamin D supplements in respiratory problems and infectious problems, musculoskeletal pain, autoimmune regulation.

“Many times, we see a lowering of antibodies or a lowering of inflammatory markers like C reactive protein, as well as improvements in blood sugar management and blood sugar control.”

The Endocrine Society, by contrast, told The Epoch Times that based on the current research, “most healthy adults under the age of 75 may not benefit from taking more vitamin D than the recommended daily allowance of vitamin D recommended by the Institute of Medicine.”

Osborne said: “The problem with a lot of research is dosing. They use low doses of vitamin D and so the strength of the outcome in the study is less than what it would be in a clinical setting. Many of these studies are giving 400 to 4800 IU of vitamin D. We start people at 100 to 150,000 units of vitamin D. The dose matters. And if you have a lot of publications using lower doses, you get a misleading body of research.”

Implications for Clinical Practice and Public Health

The new guidelines mark a departure from previous Endocrine Society recommendations regarding specific 25(OH)D levels in the following ways:

• The Endocrine Society no longer endorses the target 25(OH)D level of 30 ng/mL (75 nmol/L) suggested in the previous 2011 guideline.
• The Endocrine Society no longer endorses specific 25(OH)D levels to define vitamin D sufficiency, insufficiency, and deficiency.

“The guideline suggests clinicians perform significantly less testing, ensure that their patients are taking the IOM RDA of vitamin D and does not recommend vitamin D screening unless there are established indications (e.g., low blood calcium level),” The Endocrine Society told The Epoch Times.

Osborne said: “When it comes to nutrition, essential vitamins and minerals should be screened in every individual as a standard of care for prevention. We’re talking about prevention of major diseases, including things like diabetes, autoimmune conditions, cardiovascular disease, stroke, and arthritis. So, I think that testing and not guessing is a clinician’s obligation to their patient so that they can deliver accurate advice.”

The new guideline represents a paradigm shift toward more targeted vitamin D supplementation strategies, moving away from the previous emphasis on universal supplementation and routine testing. This approach aligns with the growing recognition that the benefits of vitamin D may be most pronounced in specific populations and those with low baseline levels, according to the guidelines.

Endocrine Society Recommendations by Population

Children and Adolescents

The June guideline suggests vitamin D supplementation for children and adolescents age one to 18 in the form of fortified foods, vitamin formulations that contain vitamin D, and/or supplementation.

“Based on the evidence examined by the guideline panel, parents should consider supplements above the daily allowance recommended by the IOM [Institute of Medicine] to prevent nutritional rickets and reduce the chance of respiratory infections,” the Endocrine Society told The Epoch Times.

While the evidence suggests potential benefits, particularly in preventing respiratory infections, the range of outcomes also included the possibility of supplementation having no effect. Therefore, the recommendation is conditional. The panel suggests vitamin D supplementation may be particularly beneficial in populations at high risk for vitamin D deficiency or respiratory infections.

The recommendation also recognizes the challenge in achieving adequate vitamin D status through sunlight exposure and diet alone, particularly in certain geographic regions or among populations with limited sun exposure.

The expert panel could not recommend an optimal daily vitamin D dose due to the wide variation used in the clinical trials, ranging from 300 to 2000 IU.

Adults Under 50 Years

For generally healthy adults under 50, the guideline suggests against routine vitamin D supplementation beyond the recommended daily allowance (RDA) established by the IOM as 600 international units (IU) daily.

“While vitamin D supplementation appears to be safe, inexpensive, and readily available, the trials identified in the systematic review did not clearly show a substantive benefit of vitamin D supplementation,” the guidelines state. “For this reason, the panel issued a conditional recommendation against routine vitamin D supplementation above what would be required to meet dietary reference guidelines.”

However, the panel determined that healthy adults in this age group might reasonably choose to take vitamin D supplements if they aren’t getting enough vitamin D from sun exposure and aren’t consistently meeting the recommended dietary intake of vitamin D from foods that contain or are fortified with it.

Adults 50 to 74 Years

As with younger adults, the guideline suggests against routine vitamin D supplementation beyond the established RDA of 600 to 800 IU daily for the 50 to 74 age group. The panel found evidence that vitamin D supplementation has little to no effect on fractures, cardiovascular events, cancer, and mortality in this population.

This recommendation challenges some previous assumptions about the benefits of widespread vitamin D supplementation in middle-aged and older adults. It underscores the importance of evidence-based practice and the need for targeted interventions based on individual risk factors rather than age alone.

Considering the well-known negative effects of very low vitamin D levels on bone health and calcium balance, the panel said that some individuals in this age group may reasonably choose to take vitamin D supplements. This is especially true for those who are unlikely to get enough vitamin D from sun exposure (such as those with darker skin, who are housebound, or who wear clothing that limits sun exposure) or who do not consistently meet the recommended intake through diet, supplements, or vitamin D-fortified foods.

Adults 75 Years and Older

For adults 75 and older, the guideline suggests vitamin D supplementation in the form of fortified foods, vitamin formulations that contain vitamin D, and/or supplementation.

This recommendation is based on the potential of vitamin D to lower mortality risk, as well as the increased risk of vitamin D deficiency in older adults due to reduced skin synthesis, decreased dietary intake, and increased prevalence of comorbidities that may affect vitamin D metabolism.

The expert panel again could not recommend an optimal vitamin D dose due to the wide variation used in the clinical trials, ranging from 400 to 3,333 IU daily equivalent.

Pregnant Women

The guideline suggests vitamin D supplementation during pregnancy in the form of fortified foods, vitamin formulations that contain vitamin D, and/or supplementation.

This recommendation recognizes the critical role of vitamin D in maternal and fetal health, particularly in supporting calcium homeostasis and immune function.

The expert panel, as elsewhere, could not recommend an optimal vitamin D dose due to the wide variation used in the clinical trials, ranging from 600 to 5000 IU daily equivalent.

Adults With Prediabetes

For adults with high-risk prediabetes, the guideline suggests vitamin D supplementation and lifestyle modification—such as regular exercise and a balanced diet—to reduce the risk of progression to diabetes.

As with the pregnancy population, the expert panel could not recommend an optimal vitamin D dose due to the wide variation used in the clinical trials, ranging from 842 to 7,543 IU daily equivalent.

This recommendation is particularly noteworthy as it points to a potential role for vitamin D in Metabolic Health and Diabetes Prevention. According to a 2022 randomized controlled trial in Expert Review of Clinical Pharmacology, elderly people with prediabetes who took vitamin D as a supplement for 12 months lowered their fasting glucose and glycated hemoglobin compared with baseline.

Screening and Testing Recommendations

The Endocrine Society’s new guideline recommends against routine screening for vitamin D levels in healthy adults, pregnant women, and those with obesity or dark complexion.

Recommendations are based on:

• Cost concerns: Routine testing could be expensive and create health inequity, especially compared to giving vitamin D supplements to everyone in certain high-risk groups.
• Unequal access: Not everyone can easily obtain accurate vitamin D tests.
• No clear evidence of benefit: No study has directly compared outcomes between a screening approach and a non-screening approach. More randomized controlled trials are needed to establish a causal relationship. “The review panel did not find evidence that a test for vitamin D level provides actionable information that leads to improved clinical outcomes,” the Endocrine Society told The Epoch Times.
• Unclear target levels: There is no agreed-upon vitamin D level that prevents disease. Even in studies where low vitamin D seemed harmful, there was not a clear cut-off point.

“Previously, the terms deficiency, insufficiency, and sufficiency were aligned with vitamin D levels based on observational studies, which can be misleading. The optimal 25-hydroxyvitamin D level for disease prevention is not known,” The Endocrine Society told the Epoch Times.

“It is likely that optimal levels will vary based on specific disease outcomes. Thus, in the absence of this data, the committee recommended against routine screening in healthy adults and do not require screening with a blood test for 25-hydroxyvitamin D unless they have established indications (e.g., low blood calcium level). People with diseases that put them at risk for vitamin D deficiency should discuss possible testing and treatment with their physician,” the Endocrine Society wrote.

For anyone receiving supplementation, testing is important to follow improvements in levels.

The Endocrine Society’s 2024 clinical practice guideline on vitamin D challenges long-held assumptions about supplementation. It recommends targeted supplementation for specific groups while advising against universal screening and supplementation beyond the Dietary Reference Intake for others. These recommendations reflect the complexities of translating nutritional research into clinical practice.