Hi, everyone. I'm Dr Kenny Lin. I am a family physician and associate director of the Lancaster General Hospital Family Medicine Residency, and I blog at Common Sense Family Doctor.
Kenneth W. Lin, MD, MPH
A few months ago, my health system added a clinical decision support function to our electronic health record to reduce inappropriate ordering of vitamin D levels. Clinicians are now required to select from a list of approved indications or diagnoses (including a history of vitamin D deficiency) before ordering the test.
Although I don't know yet whether this process has had the desired effect, I felt that it was long overdue. Several years ago, I wrote an editorial that questioned the dramatic increase in vitamin D testing given the uncertainty about what level is adequate for good health and clinical trials showing that supplementing people with lower levels has no benefits for a variety of medical conditions. A more recent review of prospective studies of vitamin D supplements concluded that most correlations between vitamin D levels and outcomes in common and high-mortality conditions are unlikely to be causal.
A new Endocrine Society guideline recommends against routine measurement of vitamin D levels in healthy individuals. The guideline reinforces my current practice of not screening for vitamin D deficiency except in special situations, such as an individual with dark skin who works the night shift and rarely goes outdoors during daytime hours. But I haven't been offering empirical vitamin D supplements to the four at-risk groups identified by the Endocrine Society: children, adults older than 75 years, pregnant patients, and adults with prediabetes. The evidence behind these recommendations merits a closer look.
In exclusively or primarily breastfed infants, I follow the American Academy of Pediatrics recommendation to prescribe a daily supplement containing 400 IU of vitamin D. However, the Endocrine Society found evidence from several studies conducted in other countries that continuing supplementation throughout childhood reduces the risk for rickets and possibly reduces the incidence of respiratory infections, with few adverse effects.
Many older women, and some older men, choose to take a calcium and vitamin D supplement for bone health, even though there is scant evidence that doing so prevents fractures in community-dwelling adults without osteoporosis. The Endocrine Society's meta-analysis, however, found that 1000 adults aged 75 years or older who took an average of 900 IU of vitamin D daily for 2 years could expect to experience six fewer deaths than an identical group not taking supplements.
A typical prenatal vitamin contains 400 IU of vitamin D. Placebo-controlled trials reviewed by the Endocrine Society that gave an average of 2500 IU daily found statistically insignificant reductions in preeclampsia, intrauterine death, preterm birth, small for gestation age birth, and neonatal deaths.
Finally, the Endocrine Society's recommendation for adults with prediabetes was based on 11 trials (three conducted in the United States) that tested a daily average of 3500 IU and found a slightly lower risk for progression to diabetes (24 fewer diagnoses of type 2 diabetes per 1000 persons) in the group who took supplements.
Of the four groups highlighted by the guideline, the strongest case for vitamin D supplements is in older adults — it's hard to argue with lower mortality, even if the difference is small. Therefore, I will start suggesting that my patients over age 75 take a daily vitamin D supplement containing at least 800 IU if they aren't already doing so.
On the other hand, I don't plan to change my approach to pregnant patients (whose benefits in studies could have been due to chance), children after age 1 year (studies of children in other countries with different nutritional status may not apply to the United States), or adults with prediabetes (where we already have proven lifestyle interventions with much greater effects). In these cases, I am either unconvinced that the data support benefits for my patients, or I feel that the benefits of vitamin D supplements are small enough to be outweighed by potential harms, such as increased kidney stones.
COMMENTARY
How the New Vitamin D Guidelines Will, and Won't, Change My Practice
Kenneth W. Lin, MD, MPH
DISCLOSURES
| July 24, 2024Hi, everyone. I'm Dr Kenny Lin. I am a family physician and associate director of the Lancaster General Hospital Family Medicine Residency, and I blog at Common Sense Family Doctor.
A few months ago, my health system added a clinical decision support function to our electronic health record to reduce inappropriate ordering of vitamin D levels. Clinicians are now required to select from a list of approved indications or diagnoses (including a history of vitamin D deficiency) before ordering the test.
Although I don't know yet whether this process has had the desired effect, I felt that it was long overdue. Several years ago, I wrote an editorial that questioned the dramatic increase in vitamin D testing given the uncertainty about what level is adequate for good health and clinical trials showing that supplementing people with lower levels has no benefits for a variety of medical conditions. A more recent review of prospective studies of vitamin D supplements concluded that most correlations between vitamin D levels and outcomes in common and high-mortality conditions are unlikely to be causal.
A new Endocrine Society guideline recommends against routine measurement of vitamin D levels in healthy individuals. The guideline reinforces my current practice of not screening for vitamin D deficiency except in special situations, such as an individual with dark skin who works the night shift and rarely goes outdoors during daytime hours. But I haven't been offering empirical vitamin D supplements to the four at-risk groups identified by the Endocrine Society: children, adults older than 75 years, pregnant patients, and adults with prediabetes. The evidence behind these recommendations merits a closer look.
In exclusively or primarily breastfed infants, I follow the American Academy of Pediatrics recommendation to prescribe a daily supplement containing 400 IU of vitamin D. However, the Endocrine Society found evidence from several studies conducted in other countries that continuing supplementation throughout childhood reduces the risk for rickets and possibly reduces the incidence of respiratory infections, with few adverse effects.
Many older women, and some older men, choose to take a calcium and vitamin D supplement for bone health, even though there is scant evidence that doing so prevents fractures in community-dwelling adults without osteoporosis. The Endocrine Society's meta-analysis, however, found that 1000 adults aged 75 years or older who took an average of 900 IU of vitamin D daily for 2 years could expect to experience six fewer deaths than an identical group not taking supplements.
A typical prenatal vitamin contains 400 IU of vitamin D. Placebo-controlled trials reviewed by the Endocrine Society that gave an average of 2500 IU daily found statistically insignificant reductions in preeclampsia, intrauterine death, preterm birth, small for gestation age birth, and neonatal deaths.
Finally, the Endocrine Society's recommendation for adults with prediabetes was based on 11 trials (three conducted in the United States) that tested a daily average of 3500 IU and found a slightly lower risk for progression to diabetes (24 fewer diagnoses of type 2 diabetes per 1000 persons) in the group who took supplements.
Of the four groups highlighted by the guideline, the strongest case for vitamin D supplements is in older adults — it's hard to argue with lower mortality, even if the difference is small. Therefore, I will start suggesting that my patients over age 75 take a daily vitamin D supplement containing at least 800 IU if they aren't already doing so.
On the other hand, I don't plan to change my approach to pregnant patients (whose benefits in studies could have been due to chance), children after age 1 year (studies of children in other countries with different nutritional status may not apply to the United States), or adults with prediabetes (where we already have proven lifestyle interventions with much greater effects). In these cases, I am either unconvinced that the data support benefits for my patients, or I feel that the benefits of vitamin D supplements are small enough to be outweighed by potential harms, such as increased kidney stones.
Any views expressed above are the author's own and do not necessarily reflect the views of WebMD or Medscape.
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