Efficacy of Calcium-Containing Eggshell Powder Supplementation on Urinary Fluoride and Fluorosis Symptoms in Women in the Ethiopian Rift Valley

Abstract

Dietary calcium binds Fluoride (F), thus preventing excess F absorption. We aimed to assess the efficacy of supplementing calcium-containing Eggshell Powder (ESP) on F absorption using urine F excretion and on fluorosis symptoms. In total, 82 women (41 Intervention Group, IG; 41 Control Group, CG) were recruited; overall, 39 in each group completed the trial. Morning spot urine was collected before (baseline, BL) and after (endline, EL) the intervention that was 6-months daily supplementation with 2.4 g ESP (providing ~1000 mg of calcium). Dental, skeletal, and non-skeletal fluorosis assessments was carried out at BL and, except for dental, at EL. Relative risk (RR) and linear generalized estimating equation were used to compare outcomes between groups. At BL, urinary F excretion in the IG and CG groups was similar, ~10 mg/L. At EL, urinary F excretion in IG women was six-fold lower (β = −6.1 (95% CI: −7.1, −5.1)) compared to CG. The risk of developing skeletal and non-skeletal fluorosis were significantly (p < 0.001) reduced in the intervention group. A significant reduction in urinary F excretion and reduction in many fluorosis symptoms were observed among women supplemented with calcium-containing ESP, thus providing evidence for using this dietary calcium source for mitigation of fluorosis. Clinical trials registration: NCT03355222.

Association of Dietary Calcium Intake with Dental, Skeletal and Non-Skeletal Fluorosis among Women in the Ethiopian Rift Valley

“…The urinary F excretion in the supplemented group was six-fold lower (β = −6.1 (95% CI: −7.1, −5.1)) compared to the control group. The risk of developing skeletal and non-skeletal fluorosis was also significantly ( p < 0.001) reduced in the treatment group [ 23 ].…”

“…A community-based cross-sectional study design was conducted in two purposively selected kebeles (small administrative divisions of a district, also called villages). The women included in this cross-sectional study were eligible for a planned pilot trial on eggshell supplementation [ 23 ] as a Ca source to mitigate fluorosis symptoms [ 20 , 21 ]. The kebeles were known for having fluorosis problems [ 2 ].…”

“…In many areas of Ethiopia, dietary Ca intake, particularly of child-bearing women, is well below the recommended dietary allowance [ 22 , 23 ]. F exposure may be an added concern for women’s bone and dental health where there is low Ca intake.…”

Association Between Dietary Fluoride and Calcium Intake of School-Age Children With Symptoms of Dental and Skeletal Fluorosis in Halaba, Southern Ethiopia

“…The study design was a cross-sectional survey in the village (kebele) of Lay Arsho in the Halaba zone. In the kebele, households had been identified for a larger study [16] and those with eligible school-age children were invited to participate in this sub-study.…”

“…Dental and skeletal fluorosis assessments were done in January 2018 during a larger survey involving two kebeles [16] during which time the same study personnel also collected data from the mothers of these school-age children, including dietary calcium using a food frequency questionnaire. The dietary intake data by 24-h recall, food, and water samples were collected in January 2019.…”