The vitamin D status of prison inmates.

There is no comprehensive, systematic analysis of the vitamin D status of prisoners in the scientific literature.To investigate the vitamin D status and its determinants in US prison inmates.Given the uniformity of dietary intake amongst inmates, vitamin D status will be determined by non-dietary factors such as skin pigmentation, security level-, and the duration of incarceration.A retrospective study of 526 inmates (males, n=502, age 48.6 ± 12.5 years; females, n=24, age 44.1 ± 12.2) in Massachusetts prisons. Vitamin D sufficiency, insufficiency, and deficiency were respectively defined as a 25(OH)D concentration 75 nmol/L; 50 to 75 nmol/L; and <50 nmol/L. The Massachusetts Department of Correction Statement of Nutritional Adequacy stated that each inmate received the recommended daily allowance of vitamin D daily. Security level of incarceration was designated as minimum, medium, and maximum. Racial groups were categorized as Black, white, Asian, and Others.Serum 25(OH)D levels peaked in summer and autumn, and decreased in winter and spring. Vitamin D deficiency occurred in 50.5% of blacks, 29.3% of whites, and 14.3% of Asian inmates (p=0.007). Black inmates had significantly lower serum 25(OH)D level than white inmates at the maximum security level (p=0.015), medium security level (p=0.001), but not at the minimum security level (p=0.40). After adjusting for covariates black inmates at a maximum security level had a four-fold higher risk for vitamin D deficiency than white inmates at the same security level (OR 3.9 [95% CI 1.3-11.7].The vitamin D status of prison inmates is determined by skin pigmentation, seasons, and the security level of incarceration

The relationship between serum concentrations of 25-hydroxyvitamin D [25(OH)D] and years of incarceration.

<p>This figure shows a weakly significant relationship between the years of incarceration and serum concentration of 25(OH)D in all inmates after adjusting for age, race, season, and BMI (β = 0.09, r² = 0.07, p = 0.042). A similar investigation in inmates in the maximum security level showed no significant relationship between 25(OH)D and the duration of incarceration (β = 0.09, r² = 0.09, p = 0.49).</p

Study Flow Diagram.

<p>Study Flow Diagram.</p

Characteristics of Prison Inmates Stratified by Gender.

<p>Characteristics of Prison Inmates Stratified by Gender.</p

Proportion of Inmates with Vitamin D Deficiency, Insufficiency, and Sufficiency within each Racial Category.

<p>Proportion of Inmates with Vitamin D Deficiency, Insufficiency, and Sufficiency within each Racial Category.</p

Complex box plots of the comparison of 25-hydroxyvitamin D values of inmates stratified by both race and the security level of incarceration.

<p>This figure shows a significant difference in 25(OH)D level between the black and white inmates at both the maximum security level (p = 0.015), and the medium security level (p = 0.001), but not at the minimum security level (p = 0.40). Note: 50 nmol/L = 20 ng/mL.</p

Graph of the relationship between 25(OH)D and the seasons in black and white prisoners.

<p>Black inmates had significantly lower 25(OH)D levels in all of the seasons except for Fall.</p

Box plots of the comparison of 25-hydroxyvitamin D values of inmates stratified by race.

<p>This figure shows that black inmates have a significantly lower 25(OH)D level compared to the white inmates (p<0.001), but similar levels to inmates categorized as Others (p = 0.54). There was inadequate power to detect a difference between black (n = 107) and Asian (n = 7) inmates (p = 0.1). Note: 50 nmol/L = 20 ng/mL.</p