Low levels affected nearly half of the patients
Currently, males with eating disorders are not as likely as before to be overlooked, but their vitamin status often is, according to results from a recent study at the University of California-San Francisco.
Dr. Jason M. Nagata and coworkers recently reported that electronic medical records from May 2012 to August 2020 showed that nearly half of males 9 to 25 years of age admitted to the UCSF Hospital for treatment of malnutrition secondary to eating disorders had low 25-hydroxyvitamin D levels (J Eat Disord. 2022. 10:104). Males were more likely than females to have severe vitamin D inadequacy. (The authors believe this is the first study to report vitamin D levels specifically in a male eating disorders sample, and the first to examine sex differences in 25-hydroxyvitamin D concentrations.)
[Note: There is a great deal of debate about diagnosing vitamin D deficiency based on blood levels alone. While blood levels do indicate inadequacy, without clinical symptoms of deficiency, that particular diagnosis cannot be substantiated. Vitamin D is one of many hormonal and dietary symptoms of deficiency and one of many that contribute to bone density and osteoporosis.]
What is so important about vitamin D deficiency, particularly in males? Physiology plays a role, according to the authors. Vitamin D is a fat-soluble vitamin that is distributed into fat and muscle tissue and may be held in adipose tissue. Thus, greater fat and muscle mass is often associated with lower serum levels of vitamin D. Vitamin D influences cell growth and immune function, helps the body absorb calcium, and is essential for nervous system function. Higher protein intake and muscle-building exercise could lead to low serum levels of vitamin D, compared to restricting behaviors. Just as females, males with eating disorders have skeletal complications such as bone fractures and bone mineral density deficiencies.
Dr. Nagata and his colleagues collected data from electronic medical records of 601 patients (93 males, 472 females) presenting for inpatient hospitalization in the eating disorders program at his hospital. The patients were between 9 and 25 years of age at admission, and their eating disorder diagnosis was made by a psychiatrist or psychologist. The final study group included 565 patients (93 males and 472 females).
The average age was 15.5 years, and 44% of the males had 25-hydroxyvitamin D levels <30 nanograms (ng)/ml; 18% had levels <20 ng/ml, and 9% had levels <12 ng/ml. Severe deficiency levels, or levels <12 ng/ml) were found in about 9% of males compared to only 1.9% of females. Mean calcium levels were slightly lower among female participants (9.0 vs. 9.5 ng/ml, respectively), and mean phosphorus levels were similar. Only 3% of males were taking vitamin D or calcium supplements immediately before admission; three times as many were taking multivitamins. Overall, fewer than 11% of the males (compared to 17% of females) reported taking any calcium or vitamin D supplements or multivitamins before being admitted to the hospital.
A deficiency that affected nearly half of the patients
This pattern was very common: nearly half of the male and female teens and young adults with eating disorders who required inpatient medical stabilization had vitamin D deficiency or insufficiency on admission, yet only 3% were taking calcium or vitamin-D-specific supplements.
In addition to low vitamin D and calcium levels, other factors have been linked to bone mineral density in females and males with eating disorders. Suppression of the hypothalamic-pituitary-gonadal axis can occur with low energy intake, leading to lower estrogen and testosterone levels so critical for bone growth during adolescence. High cortisol levels can also cause further alterations in bone metabolism.
Dr. Nagata and his colleagues underscore the importance of assessing vitamin D levels among eating disorder patients, especially male teens and young adults with eating disorders.