25-Hydroxyvitamin D Status and Risk for Colorectal Cancer and Type 2 Diabetes Mellitus: A Systematic Review and Meta-Analysis of Epidemiological Studies

Abstract

Epidemiological evidence suggests an association between low vitamin D status and risk for various outcomes including cardiovascular diseases, cancer, and type 2 diabetes mellitus (T2DM). Analyzing serum 25-hydroxyvitamin D [25(OH)D] is the most established means to evaluate an individual’s vitamin D status. However, cutoff values for 25(OH)D insufficiency as well as for optimal 25(OH)D levels are controversial. This systematic review critically summarizes the epidemiological evidence regarding 25(OH)D levels and the risk for colorectal cancer and T2DM. The meta-analytical calculation revealed a pooled relative risk (RR) of 0.62 (CI 0.56–0.70; I2 = 14.7%) for colorectal cancer and an RR of 0.66 (CI 0.61–0.73; I2 = 38.6%) for T2DM when comparing individuals with the highest category of 25(OH)D with those in the lowest. A dose–response analysis showed an inverse association between 25(OH)D levels and RR for both outcomes up to concentrations of about 55 ng/mL for colorectal cancer and about 65 ng/mL for T2DM. At still higher 25(OH)D levels the RR increases slightly, consistent with a U-shaped association. In conclusion, a higher 25(OH)D status is associated with a lower risk for colorectal cancer and T2DM; however, this advantage is gradually lost as levels increase beyond 50–60 ng/mL.

Positive correlation between vitamin D receptor gene FokI polymorphism and colorectal cancer susceptibility in South‐Khorasan of Iran

“…It is believed that collaboration of environmental and genetic factors can trigger the disease. Among environmental factor, several studies proved that, vitamin D intake, and higher serum level of 25(OH) D can act in a protective way against CRC . Studies reported that in advanced stage of CRC, vitamin D receptor expression has reduced dramatically so that anti‐proliferative function of vitamin D disappeared .…”

“…Among environmental factor, several studies proved that, vitamin D intake, and higher serum level of 25(OH) D can act in a protective way against CRC. 14,15 Studies reported that in advanced stage of CRC, vitamin D receptor expression has reduced dramatically so that anti-proliferative function of vitamin D disappeared. 16 Since the active form of vitamin D performs its cellular function via VDR, 17 it is logical to investigate the role of VDR variations in alteration of colorectal cancer susceptibility.…”

The Level of Vitamin D among Diabetic Patients

“…Studies revealed an inverse association between vitamin D level and colorectal cancer in type 2 diabetics with the relative risk of 0.62. However, the benefit of vitamin D supplementation is lost when the levels of vitamin D are over the upper limit of the normal range 3 .…”

“…Vitamin D insufficiency is often detected in diabetic patients, and it is believed to be linked to the disease development and severity 1,2,3 .…”

Нутритивна І Медикаментозна Корекція Дефіциту Кальцію І Вітаміну D У Дітей

“…Кальций (Са) является самым распространенным макроэлементом в организме человека. Полагают, что 99 % всего пула Са локализуется в костной тка ни, и только 1 % Са находится вне костной системы, выполняя многочисленные физиологические функ ции на самых разнообразных уровнях организации клеток, органов и систем [14,20]. Общее содержание Са в организме человека опосредовано количеством Са в ежедневно употребляемых продуктах питания, уровнем всасывания в пищеварительном тракте и активностью выведения ионов Са с калом и мочой.…”