Vitamin D and Calcium Supplementation and Urolithiasis: A Controversial and Multifaceted Relationship

Association between milk consumption and kidney stones in U.S. adults: results from NHANES 2007-2018

Background

Dietary strategies play a crucial role in the prevention of kidney stones. While milk is known for its rich nutritional content, its impact on kidney stone formation remains unclear. This study aimed to examine the relationship between milk consumption and the risk of kidney stones among U.S. adults.

Methods

We included 24,620 participants aged 20 and older from the National Health and Nutrition Examination Survey (2007-2018). Milk consumption was defined based on each participant's response to the questionnaire item on "Past 30 day milk product consumption." Kidney stones history was self-reported by participants. The analysis employed weighted multivariate logistic regression models, followed by subgroup analyses for result validation, and explored the age-related dynamics of milk consumption's effect on kidney stone risk using a restricted cubic spline model.

Results

Adjusted findings revealed that higher milk intake was associated with a decreased risk of kidney stones (odds ratio [OR] = 0.90, 95% confidence interval [CI] 0.85-0.96), notably among women (OR = 0.86, 95% CI 0.80-0.92) but not significantly in men (OR = 0.94, 95% CI 0.86-1.02). Smoothed curves across all ages showed that women consuming milk had a lower incidence of kidney stones than those who did not, particularly with regular consumption.

Conclusion

This study uncovered that across all age groups, higher frequency of milk consumption in women is associated with a reduced risk of kidney stones. However, further prospective cohort studies are needed to confirm this finding.

Urinary stone in infants; should vitamin D prophylaxis be stopped?

BACKGROUND

This study investigated the effect of the discontinuation of vitamin D supplementation on kidney stone formation in children under 2 years of age.

METHODS

This study involved a retrospective analysis of two patient groups. The first group comprised postoperative patients who were stone-free, while the second group consisted of asymptomatic patients with kidney stones. The patients who discontinued vitamin D supplementation and those who continued were compared in terms of stone formation and stone size progression. The data collected included patient characteristics, stone size measurements, and laboratory results.

RESULTS

The findings showed that the discontinuation of vitamin D supplementation was not associated with kidney stone formation or the progression of stone size in either group. For patients who were stone-free on ultrasonography 1 month after the operation, according to the 12-month ultrasonography evaluation, in the group that discontinued vitamin D, 42 (78%) patients had no stones, 6 (11%) patients had stones larger than 3 mm, and 6 (11%) patients had microlithiasis. However, in the group that continued vitamin D, 49 (72%) patients were stone-free, 10 (15%) patients had stones larger than 3 mm, and 9 (13%) patients had microlithiasis. There was no difference between the groups in terms of stone status at 12 months (p = 0.76). For patients with asymptomatic kidney stones, the initial stone sizes were similar between the groups (p = 0.74). During the 6th month of ultrasound, the changes in stone size were 1.76 ± 1.81 mm and 1.79 ± 1.75 mm for the two groups, respectively (p = 0.9). During the 12-month ultrasound measurement, the changes in stone size were 1.98 ± 2.93 mm and 2.60 ± 2.48 mm for the two groups, respectively (p = 0.09).

CONCLUSIONS

We believe that more research is needed to make definitive recommendations regarding vitamin D prophylaxis in infants with kidney stones. Although the first objective of our study is not conclusively proven with the current findings, we recommend continued vitamin D prophylaxis in infants with urolithiasis.

Multivitamins co-intake can reduce the prevalence of kidney stones: a large-scale cross-sectional study

BACKGROUND

This research aimed to explore the association between changes in the intake of common individual vitamins and combinations of vitamins and the prevalence of kidney calculi.

METHODS

We used data from NHANES to investigate the association between nine common vitamins and kidney stone prevalence. Participants were clustered into several vitamin exposure patterns using an unsupervised K-means clustering method. We used logistic regression models and restrictive cubic spline curves to explore the influence of vitamins.

RESULTS

The regression model exposed that compared to lower intake, high intake of vitamin B6 [Q4: OR (95% CI) = 0.76 (0.62, 0.93)], vitamin C [Q4: OR (95% CI) = 0.73 (0.59, 0.90)] and vitamin D [Q4: OR (95% CI) = 0.77 (0.64, 0.94)] individually exerted protective effects against the prevalence of kidney stones. Furthermore, the restrictive cubic spline analysis showed that the protective effect against the prevalence of kidney stones is enhanced as the take of vitamin B6 and vitamin D increased. Moreover, with the increase in vitamin C intake, its protective effect may turn into a risk factor. Regarding mixed exposure, Cluster 4 exhibited a significant protective effect against kidney stones compared with Cluster 1 [Model 3: OR (95% CI) = 0.79 (0.64, 0.98)].

CONCLUSIONS

Our research revealed that high levels of vitamin B6 and vitamin D intake were linked to a lower prevalence of kidney stone. With the gradual increase intake of vitamin C, the prevalence of kidney calculi decreased first and then increased. In addition, the co-exposure of nine vitamins is a protective factor for kidney stone disease.

Diet-induced nephrocalcinosis in aquarium-raised juvenile spotted wolffish Anarhichas minor

Wolffish are regularly housed in aquaria, but little data on their husbandry and health is available for caretakers. High occurrence rates of nephrocalcinosis and urolithiasis have been observed in Atlantic Anarhichas lupus and spotted A. minor wolffish housed at 2 Canadian zoological institutions. To explore the effect of diet on nephrocalcinosis and urolithiasis development, a 16 mo prospective study was conducted. A total of 32 juvenile spotted wolffish were randomly assigned to one of 4 experimental groups fed exclusively with the following diet: (1) Skretting® Europa 18 pellets; (2) Mazuri® LS Aquatic Carni-Blend Diet Formula; (3) vitamin-supplemented fish-based diet, and (4) vitamin-supplemented invertebrate-based diet. Urinalysis, radiographs, and complete necropsies were performed at the end of the study. None of the wolffish developed uroliths during the study period. All specimens fed with the fish-based and invertebrate-based diets developed nephrocalcinosis, whereas this condition was seen in 12.5 and 0% of the fish in the Skretting® and Mazuri® groups, respectively. Affected wolffish often presented with oxalate crystalluria and increased radiodensity of the posterior kidneys. Urinalysis and radiographic study were considered useful in the antemortem diagnosis of nephrocalcinosis. None of the previously published risk factors for the development of nephrocalcinosis in fish were supported by the results of this study. However, nutritional analyses of the 4 diets suggest that high dietary levels of gelatin or vitamin C or low levels of vitamin E could be potential risk factors for the development of nephrocalcinosis in spotted wolffish and thus warrant further study.