Vitamin D

Olivia C. Welter, PharmD

The Endocrine Society, with input from a panel of experts, developed a new guideline published in the August 2024 issue of the Journal of Clinical Endocrinology & Metabolism that presented the most appropriate indications for vitamin D supplementation and screening for vitamin D deficiency in generally healthy individuals.

Many studies have been conducted that investigate associations between vitamin D levels and common disorders, but existing guidelines from other organizations primarily detail recommendations for preventing fractures and skeletal disease, such as osteoporosis in older adults.

The new guideline replaces the Endocrine Society’s previous guidance document, which was published over a decade ago in 2011. The authors considered not only musculoskeletal implications of vitamin D supplementation, but also how vitamin D can affect pregnancy, respiratory diseases, and endocrine disorders.

The authors of the new guideline recognized that patients may over supplement vitamin D and clinicians may overscreen for deficiency unnecessarily, adding to burdensome costs and time considerations for patients and the health care system.

Supplementation recommendations

According to the guideline, children and adolescents between the ages of 1 year and 18 years would benefit from empiric vitamin D supplementation to prevent nutritional rickets and potentially lower the risk of respiratory tract infections.

This supplementation can include regular consumption of foods fortified with vitamin D such as milk products, orange juice, and various fish or through vitamin D in the form of pills or drops. In clinical trials investigating vitamin D to prevent respiratory disease, the weighted average daily dose for children was around 1,200 IU (30 μg).

For nonpregnant adults up to age 74, the guideline authors do not recommend empiric vitamin D supplementation. Adults in this age range should follow the appropriate recommended dietary allowance established by the Institutes of Medicine, which is 600 IU (15 µg) daily for adults who fall between 50 to 70 years old and 800 IU (15 µg) daily for those over 70 years old.

The guideline recommends empiric vitamin D supplementation for adults 75 and older to lower the risk of mortality. Similar to the recommendation for children, adults in this age range can consume fortified food daily or take a vitamin D supplement. The weighted average daily dose from clinical trials for this population was 900 IU (23 µg).

The guideline authors suggest that empiric vitamin D supplementation at 2,500 IU (63 µg) per day during pregnancy can lower the risk of preeclampsia, intrauterine mortality, preterm birth, small for gestational age, and neonatal mortality. Depending on the formulation, pregnant patients may achieve adequate vitamin D supplementation through their daily prenatal vitamin, although vitamin D concentrations can vary widely between supplements. Pregnant individuals can also supplement vitamin D through fortified foods or standard vitamin D pills or drops.

Adults diagnosed with high-risk prediabetes can also receive empiric vitamin D supplementation, according to the guideline. Supplementation in this population can potentially reduce the risk of disease progression to diabetes. The average dose across relevant clinical trials was 3,500 IU (88 µg) daily. However, the panel noted that lifestyle modification is necessary in addition to vitamin D supplementation in individuals with prediabetes.

For adults 50 years or older who have an indication for vitamin D supplementation, the guideline authors recommend taking a daily, lower-dose vitamin D formulation instead of nondaily, higher-dose vitamin D.

Screening recommendations

For generally healthy adults of any age who do not otherwise have established indications for serum vitamin D screening, including pregnant individuals, the panel suggested against routine screening and follow up of vitamin D levels.

However, if an adult has an indication such as hypocalcemia, clinicians can perform routine screening to assess serum concentrations of vitamin D and adjust treatment plans for vitamin D deficiency.

Role of pharmacists

Pharmacists in any clinical practice setting can use the recommendations outlined in this guideline to tailor patient medication regimens based on their risk for vitamin D deficiency. Depending on a patient’s symptom profile, pharmacists can either recommend or discourage routine screening.

Pharmacists can also work with pregnant patients to create a plan for prenatal supplementation, including vitamin D. Additionally, pharmacists can counsel generally healthy patients on the appropriate daily dietary allowance for vitamin D and explain how different fortified foods can help achieve adequate serum levels of vitamin D, noting that vitamin D supplementation isn’t always necessary.  ■