Macronutrient Intake Influences the Effect of 25-Hydroxy-Vitamin D Status on Metabolic Syndrome Outcomes in African American Girls

Abstract

The objectives were to determine the effect of macronutrient modification on vitamin D status and if change in 25-hydroxy-vitamin D concentration influences components of metabolic syndrome in obese African American girls. Methods. Five-week intervention using reduced CHO (43% carbohydrate; 27% fat: SPEC) versus standard CHO (55% carbohydrate; 40% fat: STAN) eucaloric diet. Subjects were 28 obese African American females, aged 9–14 years. Dual energy X-ray absorptiometry and meal test were performed at baseline and five weeks. Results. Approximately 30% of girls had metabolic syndrome. Serum 25OHD increased in both groups at five weeks [STAN: 20.3 ± 1.1 to 22.4 ± 1.1 (P < 0.05) versus SPEC: 16.1 ± 1.0 to 16.8 ± 1.0 (P = 0.05)]. The STAN group, increased 25OHD concentration over five weeks (P < 0.05), which was positively related to triglycerides (P < 0.001) and inversely associated with total cholesterol (P < 0.001) and LDL (P < 0.001). The SPEC group, had increase in 25OHD (P = 0.05), which was positively related to fasting insulin (P < 0.001) and insulin sensitivity while inversely associated with fasting glucose (P < 0.05). The contribution of vitamin D status to metabolic syndrome parameters differs according to macronutrient intake. Improvement in 25OHD may improve fasting glucose, insulin sensitivity, and LDL; however, macronutrient intake warrants consideration.

The relation of vitamin D status with metabolic syndrome in childhood and adolescence: an update

“…Also in a trial that examined the effect of micronutrient modification on vitamin D status, it was shown that a 5-week intervention of reduced carbohydrate and fat on obese AA females led to an increase of 25(OH)D levels. Consequently, that increase was positively correlated with I F and IS and inversely associated with G F (65). Another RCT study in black normotensive adolescents examined the effect of a 12-week vitamin D supplementation (2000 IU/day) on arterial stiffness as measured by pulse wave velocity (PWV) (66).…”

African American Females: A Potential Link Between Vitamin D Insufficiency and Type-2 Diabetes

“…The authors also observed a positive relationship between increased vitamin D and fasting insulin and insulin sensitivity [58]. Similarly, an analysis of the cross-sectional NHANES III to determine an association between serum 25(OH) D, ethnicity and diabetes risk, was conducted.…”

“…Newton et al [58] found an inverse association between fasting glucose and increased vitamin D consumption within a group of African American girls in a clinical study. The authors also observed a positive relationship between increased vitamin D and fasting insulin and insulin sensitivity [58].…”

“…A number of studies have suggested a relationship between vitamin D status and insulin sensitivity/fasting blood glucose as well as T2D risk ( 13,43,58,62,63]. For example, the intake of vitamin D was inversely associated with high blood glucose, low HDL, and the risk of developing metabolic syndrome in African Americans and whites [27].…”

“…The intake of vitamin D was inversely associated with high blood glucose, low HDL, and the risk of developing metabolic syndrome [27] Obese African American (28 subjects) Female An inverse association was found between fasting glucose and increased vitamin D consumption within this group, as well as a positive relationship between increased vitamin D and fasting insulin and insulin sensitivity [58] Non-Hispanic white (2,766 subjects), nonHispanic black (1,736 subjects), and Mexican American (1,726 subjects) Male & Female Insulin resistance was found to be higher among non-Hispanic blacks compared to whites, and the diabetes risk varied inversely across quartiles of 25 (OH) D in a dosedependent manner [62] 320 subjects, race not specified Female Vitamin D deficiency was correlated with increased body fat and glucose levels, and decreased insulin sensitivity [64] 10 T2D patients, race not specified Female Vitamin D deficiency was suggested to contribute to the impairment of insulin secretion and insulin action in T2D patients [65] 100 T2D patients, race not specified Male & Female Insulin resistance and fasting blood glucose were decreased in T2D patients who received vitamin D supplementation [66] 147 pregnant women, race not specified Female Serum 25 (OH) D and blood glucose levels have been found to be independent predictors of HbA1c levels (which is the strongest predictor for T2D incidence) [68] 120 T2D patients, race not specified…”