Effects of Different Dietary Interventions on Calcitriol, Parathyroid Hormone, Calcium, and Phosphorus: Results from the DASH Trial

Abstract

The “Dietary Approaches to Stop Hypertension” (DASH) diet, rich in fiber and low-fat dairy, effectively lowers blood pressure. DASH’s effect on calcitriol and other markers of bone-mineral metabolism is unknown. This secondary analysis of the DASH trial aimed to determine the effect of dietary patterns on blood concentrations of calcitriol, parathyroid hormone (PTH), ionized calcium, and urinary excretion of calcium and phosphorus. Outcomes were available in 334 participants in the trial. After a 3-week run-in on the control diet, participants were randomized to control, fruits and vegetables (F&V), or DASH diets. Outcomes were assessed at the end of run-in, and during the last week of the intervention period. Mean age of participants was 45.7 ± 10.7 years, 46% female, and 57% African-American. Mean ± Standard Deviation(SD) baseline serum concentrations of calcitriol, PTH, and ionized calcium were 37.8 ± 9.2 pg/mL, 46.1 ± 18.5 pg/mL and 5.2 ± 0.23 mg/dL, respectively. Mean (±SD) urinary calcium and phosphorus excretions were 150.1 ± 77.8 and 708.0 ± 251.8 mg/24 h, respectively. Compared with control, DASH reduced calcitriol −3.32 pg/mL (p = 0.004). Otherwise, there was no significant effect on other biomarkers. DASH lowered serum calcitriol perhaps more among African-Americans. These results raise important questions about the interpretation and clinical significance of low calcitriol concentrations in the setting of recommended diets.

Effect of Extra Virgin Olive Oil and Traditional Brazilian Diet on the Bone Health Parameters of Severely Obese Adults: A Randomized Controlled Trial

“…Once increases in PTH activate bone remodeling, increasing blood calcium levels, a decrease in PTH may be beneficial, favoring the aggregation of calcium in the bones, whereas this mineral exerts feedback inhibition on the PTH glands as well [57]. In this study, the DieTBra improved levels of this bone marker, suggesting a better balance of PTH levels after a nutritional intervention with a healthy dietary pattern, different from another study with the Dietary Approaches to Stop Hypertension (DASH), in which there was an increase only in calcitriol levels without a difference for PTH and further bone parameters during three weeks of follow-up [58].…”

The Association Between Dietary Inflammatory Index and Parathyroid Hormone in Adults With/Without Chronic Kidney Disease

“…Cheung et al (45) suggested that low dietary magnesium intake could alter the vitamin D-PTH relationship in adults who were overweight or obese. In another study assessing the effect of the dietary approaches to stop hypertension (DASH) diet, which is rich in fiber and low-fat dairy and is useful for lowering blood pressure on the PTH level, no significant effect was observed (46). Additionally, the cause-and-effect relationship between PTH and inflammation still remains controversial.…”

A Systematic Review of Literature on Representation of Racial and Ethnic Minority Groups in Clinical Nutrition Interventions

“…Study stratification by health outcomes is depicted in Figure 2. 41 , calcitriol (men only) 31 , TC, LDL and HDL 35 , and CHD risk 25 on the DASH diet in Black people compared to Whites. In the DASH-sodium study, the reductions in BP between the lower and higher sodium levels on the control diet were greater in Black people versus Whites 47 .…”