Prevalence of interpersonal violence against women and men in New Zealand: results of a cross-sectional study.

OBJECTIVE: To determine prevalence rates of non-partner and partner violence (IPV) in men and women from a population-based study. METHODS: We recruited 2,887 randomly selected respondents (1,464 women and 1,423 men) from three regions of New Zealand between 2017 and 2019. Face-to-face interviews using a questionnaire adapted from the WHO multi-country study on violence against women was used for data collection. RESULTS: Physical violence by non-partners was most commonly experienced by men (39.9% lifetime exposure) compared with 11.9% of women. More women (8.2%) experienced lifetime non-partner sexual violence compared with men (2.2%). About 29% of men and women reported at least one act of physical-IPV in their lifetime, and about 12.4% of women and 2.1% of men reported at least one act of lifetime sexual IPV. More women than men reported serious injuries, fear, and physical and mental health impacts following IPV experience. CONCLUSIONS: These findings indicate high prevalence of interpersonal violence exposure in the population, with marked gender differences in the types and impacts of violence reported. IMPLICATIONS FOR PUBLIC HEALTH: Study results call for the urgent implementation of violence prevention programs, and funding for both services to rehabilitate people who have perpetrated violence and services to support recovery of those affected.

Factors influencing help-seeking by those who have experienced intimate partner violence: Results from a New Zealand population-based study.

BACKGROUND: There is limited information about what influences help-seeking following experience of intimate partner violence (IPV). This study investigated determinants of formal and informal help-seeking by those who had experienced lifetime physical, sexual or psychological IPV. METHODS: A cross-sectional population-based New Zealand study conducted from 2017 to 2019 recruited 2,887 participants (1,464 women and 1,423 men) aged 16 years and older. Face-to-face interviews were conducted. Of these, 1,373 participants experienced physical, sexual or psychological IPV. Two series of logistic regressions were conducted: 1) comparing those who sought help with those who did not, and 2) comparing those who had not sought help with those who sought informal help only, or with those who also sought formal help. RESULTS: Of the 1,373 participants who reported experience of physical, sexual or psychological IPV 835 participants (71.3% of women and 49.0% of men) sought some form of help. In both genders self-reported physical and mental health or work-related IPV impacts were significantly associated with help-seeking. Experiencing only one form of IPV was associated with lower odds of seeking formal help by women (Adjusted odds ratio = 0.38; 95%CI = 0.15, 0.92 for physical/sexual only and AOR = 0.37, 95%CI = 0.22, 0.64 for psychological only) compared to those experiencing concurrent types of IPV. CONCLUSION AND IMPLICATIONS: Although there were gender differences in help-seeking, for both women and men the experience of greater impacts associated with IPV exposure increased the likelihood of help-seeking. Agencies providing services for people who are experiencing IPV need to be equipped to identify and respond to multiple forms of IPV, and prepared to address the suite of impacts experienced.

Lifetime Prevalence of Intimate Partner Violence and Disability: Results From a Population-Based Study in New Zealand.

INTRODUCTION: There is no population-based study on prevalence rates for all forms of intimate partner violence experienced by people with different types of disabilities in New Zealand. This study compares the reported lifetime prevalence of intimate partner violence (physical, sexual, psychological, controlling behaviors, and economic abuse) for people with different types of disabilities with that reported by those without disabilities and tests whether there is a gender difference. METHODS: From March 2017 to March 2019, a total of 2,888 women and men aged ≥16 years participated in a cross-sectional study in New Zealand using a cluster random sampling method. Face-to-face interviews were used for data collection. The WHO Multi-country Study questionnaire was employed as the data collection tool. Logistic regression was conducted, and AORs were reported. RESULTS: Those with any disability reported significantly higher rates of most forms of intimate partner violence than those without disabilities, among both genders, including physical intimate partner violence (AOR=1.80, 95% CI=1.32, 2.47 for women, AOR=2.44, 95% CI=1.72, 3.45 for men) and psychological and economic abuse. Women with disabilities were more likely to report experiences of sexual intimate partner violence than men (range =13.5-17.1% vs 4.0%-21.2% in men). Men with intellectual disability were more likely to report physical intimate partner violence than women with intellectual disability (60.5% in men and 36.0% in women). CONCLUSIONS: People with disabilities report experiencing a significantly high lifetime prevalence of intimate partner violence compared with people without disabilities. The results warrant policy and practice changes to identify early signs of abuse and intervene accordingly and warrant an investment in targeted violence prevention programs.

Prevalence of Nonpartner Physical and Sexual Violence Against People With Disabilities.

INTRODUCTION: This study aims to determine the prevalence rates of nonpartner physical and sexual violence in men and women with different disabilities compared with those in people without disabilities. METHODS: Face-to-face interviews were conducted in 3 regions of New Zealand (2017-2019), and 2,887 randomly selected respondents participated (1,464 women, 1,423 men). Respondents provided information on the disability types (physical, intellectual, psychological, none) experienced and on the experience of physical and sexual violence since age 15 years. Analysis was conducted in 2020-2021. RESULTS: More people with disabilities reported nonpartner physical and sexual violence experience than those without disabilities. For women, 15.4% of those with disabilities experienced lifetime nonpartner physical violence, and 11.1% experienced lifetime nonpartner sexual violence. For men with disabilities, 56.2% experienced lifetime nonpartner physical violence, and 5.6% experienced lifetime nonpartner sexual violence. Women and men with psychological disabilities reported the highest prevalence rates of nonpartner physical and sexual violence. The main perpetrators of nonpartner physical violence for women with disabilities were parents and relatives (59.7%), whereas for men with disabilities, strangers (59.3%) were the main perpetrators. Among people with disabilities who reported nonpartner sexual violence, 43.5% of women and 60.0% of men never sought help. CONCLUSIONS: This is one of the few studies globally reporting on the prevalence of nonpartner violence in both men and women with different disability types. It contributes information on the gender and relationships of those who perpetrated the violence. Findings highlight the need for violence prevention and intervention programs that are inclusive of and responsive to those with different disability types.

Change in prevalence rates of physical and sexual intimate partner violence against women: data from two cross-sectional studies in New Zealand, 2003 and 2019.

OBJECTIVES: To explore changes in reported prevalence of physical and sexual intimate partner violence (IPV) between 2003 and 2019. The impact of sociodemographic differences between the two samples and between group differences were also examined. Changes in attitudes supportive of violence and in help-seeking behaviour following disclosure were also explored. DESIGN: Two cross-sectional studies. SETTING AND PARTICIPANTS: Cross-sectional studies on family violence conducted in New Zealand in 2003 and 2019. Ever-partnered female respondents aged 18-64 years old were included (2003 n=2674, 2019 n=944). MAIN OUTCOME MEASURES: Prevalence rates of lifetime and past 12-month physical and sexual IPV, attitudes towards gender roles and acceptability of a man hitting his wife, help sought and received following disclosure were compared between the study years. RESULTS: Lifetime prevalence of physical IPV was unchanged between 2003 and 2019 (AOR=0.89; 95% CI 0.73 to 1.08). There was a significant decrease in the proportion of women who reported experiencing 12-month physical IPV (AOR=0.53; 95% CI 0.29 to 0.97). Small reductions in rates for lifetime sexual IPV were also observed (AOR=0.74; 95% CI 0.59 to 0.95). In 2019, fewer women agreed with one or more statements supportive of traditional gender roles (48.1% (95% CI 45.7% to 50.5%) in 2003; 38.4% (95% CI 33.8% to 43.2%) in 2019). A significant decrease was noted in the proportion of women who sought help from informal sources (from 71.3% (95% CI 68.1% to 74.2%) in 2003 to 64.6% (95% CI 58.7% to 70.1%) in 2019). No significant changes in seeking help from formal sources, or perceived helpfulness from any source were noted. CONCLUSION: While the reductions in 12-month physical and lifetime sexual IPV are positive, prevention efforts need to be established, maintained and strengthened to address the substantial lifetime prevalence of IPV. Efforts to strengthen responses from formal and informal sources continue to be needed.

Change in prevalence of psychological and economic abuse, and controlling behaviours against women by an intimate partner in two cross-sectional studies in New Zealand, 2003 and 2019.

OBJECTIVES: Changes in reported lifetime prevalence of psychological abuse, controlling behaviours and economic abuse between 2003 and 2019, and past 12-month prevalence of psychological abuse by an intimate partner were examined. DESIGN: Cross-sectional analysis. SETTING AND PARTICIPANTS: Data came from two surveys of family violence in New Zealand, conducted in 2003 and 2019. Respondents were ever partnered women aged 18-64 years old (2003 n=2673; 2019 n=935). MAIN OUTCOME MEASURES: Prevalence rates for psychological abuse, controlling behaviours and economic abuse were compared between the two study years using logistic regression. Sociodemographic and economic correlates of each abuse subtype were investigated. Interactions were examined between sociodemographic factors and the study year for reported prevalence rates. RESULTS: There was a reduction in reported past 12-month experience of two or more acts of psychological intimate partner violence (IPV) from 8.4% (95% CI 7.3 to 9.6) in 2003 to 4.7% (95% CI 3.2 to 6.2) in 2019. The reported lifetime prevalence of two or more acts of controlling behaviours increased from 8.2% in 2003 (95% CI 7.0 to 9.5) to 13.4% in 2019 (95% CI 11.0 to 15.7). Lifetime prevalence of economic IPV also increased from 4.5% in 2003 (95% CI 3.5 to 5.5) to 8.9% in 2019 (95% CI 6.7 to 11.1). Those who were divorced/separated or cohabiting, and those living in the most deprived areas were more likely to report past year psychological IPV, lifetime controlling behaviours and economic abuse. A higher proportion of women who were married or cohabiting reported controlling behaviours in 2019 compared with 2003. CONCLUSION: While the reduction in reported past year psychological IPV is encouraging, the increase in the lifetime prevalence of controlling behaviours and economic abuse from 2003 to 2019 is worth critical evaluation. Results highlight potential gaps in current IPV prevention programmes, the need to identify and address underlying drivers of abusive behaviour and the importance of measuring multiple forms of IPV independently.

Modifiable Early Childhood Risk Factors for Obesity at Age Four Years.

Background: Childhood obesity is associated with an increased risk of adult obesity and related chronic disease. Our aim was to identify modifiable exposures that are independently associated with obesity in the preschool age group. Methods: A prospective cohort study of 5734 children in New Zealand with anthropometric measurements was completed at age 4.5 years. The modifiable exposures of interest, measured at age 9 months and 2 years, were: food security during infancy; and, at age 2 years, screen time; sleep duration; and takeaway food and soft drink intake. The risk of obesity independently associated with each exposure was determined using Binomial and Poisson regression and described using adjusted risk ratios (RRs) and 95% confidence intervals (CIs), after controlling for confounding variables including gender, ethnicity, birth weight, and mother's age. The probability of obesity given cumulative exposures to the four risk factors and the population attributable fraction (PAF) were estimated. Results: Lower food security during infancy (1 hour/day; RR = 1.22; 95% CI : 1.01-1.48), shorter sleep duration (≤11.5 hours/day; RR = 1.30; 95% CI : 1.05-1.61), and weekly to daily consumption of takeaway/soft drink (RR = 1.25, 95% CI : 1.00-1.57) were independently associated with an increased risk of obesity at age 4.5 years. The cumulative PAF for childhood obesity was 42.9%, under an ideal scenario where all risk factors were eliminated. Conclusion: Exposure to modifiable factors by age 2 years is associated with obesity at age 4.5 years. Interventions to prevent childhood obesity need to be effective during infancy.

Monthly high-dose vitamin D supplementation does not increase kidney stone risk or serum calcium: results from a randomized controlled trial.

BACKGROUND: A growing number of randomized controlled trials (RCTs) are investigating the potential health benefits of high-dose vitamin D supplementation. However, there are limited RCT data on the safety of calcium-related adverse effects. OBJECTIVE: We investigated the incidence of kidney stone and hypercalcemia events in a large, population-based RCT of vitamin D supplementation. DESIGN: The Vitamin D Assessment (ViDA) study was a randomized, double-blind, placebo-controlled trial of vitamin D supplementation in 5110 participants in Auckland, New Zealand. This trial investigated the impact of monthly 100,000 IU vitamin D3 supplementation over several years on cardiovascular events, respiratory infections, and falls/fractures. Participants provided information about recent kidney stone events in regular questionnaires sent to them with study capsules. Hospitalization data for kidney stones were collected from health authorities. Serum calcium was measured in an 8% subsample of participants who returned annually for blood tests. HRs of time to the first kidney stone event were calculated by Cox regression. RESULTS: During a median follow-up of 3.3 y, 158 participants reported a kidney stone event (76 vitamin D, 82 placebo). The HR of reporting the first kidney stone event was 0.90 (95% CI: 0.66, 1.23; P = 0.51) for participants in the vitamin D arm compared with the placebo arm. There were 18 urolithiasis events in the hospitalization records: 7 in the vitamin D arm and 11 from the placebo arm. The HR to the first hospitalization urolithiasis event was 0.62 (95% CI: 0.24, 1.26; P = 0.30) in the vitamin D arm compared with the placebo arm. From the subsample annual blood test, there was no case of hypercalcemia in the vitamin D arm, compared with 1 in the placebo arm. CONCLUSION: Over a median of 3.3 y, monthly supplementation with 100,000 IU vitamin D3 did not affect the incidence rate of kidney stone events, or hypercalcemia. This study was registered at clinicaltrials.gov as ACTRN12611000402943.

Monthly high-dose vitamin D3 supplementation and self-reported adverse events in a 4-year randomized controlled trial.

BACKGROUND: The use of high-dose vitamin D supplementation has increased in recent years. However, relatively little is known about the safety of long-term high doses. AIMS: To investigate the safety of a monthly high-dose of vitamin D3 supplementation taken for up to 4 years. METHODS: Data were collected in a randomized, double blind, placebo-controlled trial of 5108 adults aged 50-84 years old from Auckland, New Zealand. Participants were given monthly doses of 100,000 IU vitamin D3 or placebo, for a median of 3.3 years (range 2.5-4.2 years). They answered an open-ended question in a monthly questionnaire about any adverse events they attributed to the study capsules, which were coded blindly. Incidence rates per person months were calculated for categories of adverse events. Cox regression model used to calculate hazard ratio of time to first adverse-event. RESULTS: In total, 419 (16.5%) participants taking vitamin D and 399 (15.8%) taking placebo reported ≥1 adverse event. Compared to placebo, the hazard ratio (HR) of reporting first adverse event in the vitamin D group was 1.03 (95% CI: 0.90, 1.18; p = 0.63). Despite a slightly higher incidence of recurrent adverse events in vitamin D arm, the incidence rate ratio (1.17) was not significantly higher in vitamin D (95% CI: 0.97, 1.41; p = 0.10). All regression results were adjusted for age, sex, and ethnicity. There was no difference between study arms in terms of participants' allocation perception (p = 0.52). CONCLUSION: Monthly supplementation of 100,000 IU vitamin D3 for a median of 3.3 years did not affect participant-reported adverse events. TRIAL REGISTRATION: clinicaltrials.gov Identifier: ACTRN12611000402943; https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?ACTRN=ACTRN12611000402943.

Association between serum 25-hydroxyvitamin D levels and self-reported chronic pain in older adults: A cross-sectional analysis from the ViDA study.

Chronic pain is a major contributor to the global burden of disability. Prior studies on the association between serum 25-hydroxyvitamin D (25(OH)D) levels and chronic pain have yielded mixed results. The Vitamin D Assessment study, a large randomized controlled trial from New Zealand, offered the opportunity to examine this association in data collected at baseline in all participants, and among those with arthritis or depression. A total of 5110 participants aged 50-84 years were recruited from community general practices. Chronic pain (lasting ≥6 months) and other baseline characteristics were collected at baseline interview. Serum 25(OH)D concentration was measured by liquid chromatography-tandem mass spectrometry. Associations between 25(OH)D levels and chronic pain were explored using multivariable log-binomial regression to estimate relative risks (RRs). Out of 5049 participants with complete data, 871 (17%) reported having this clinical outcome, and 1254 (25%) had a 25(OH)D concentration <50 nmol/L. There was no significant association between 25(OH)D and chronic pain, with vitamin D status categorized in four groups: <25.0, 25.0-49.9, 50.0-74.9, and ≥75.0 nmol/L (the highest group as reference). The unadjusted RRs were 1.09, 1.10, and 1.08, respectively (Ptrend = 0.24). Adjustment for demographics, lifestyle, BMI, medical history, prescription of analgesics and vitamin D supplements did not change this finding. Similar non-significant results were observed in participants with arthritis (n = 1732) or depression (n = 528). In this multi-ethnic, community-selected sample of older adults in New Zealand, serum 25(OH)D levels were not associated with chronic pain. These results do not support a role for low vitamin D status in the prevalence of chronic pain in older adults.

The association between vitamin D concentration and pain: a systematic review and meta-analysis.

OBJECTIVE: Pain-related conditions, such as chronic widespread pain and fibromyalgia, are major burdens for individuals and the health system. Evidence from previous research on the association between circulating 25-hydroxyvitamin D (25(OH)D) concentrations and pain is conflicting. Thus, we aimed to determine if there is an association between mean 25(OH)D concentration (primary aim), or proportion of hypovitaminosis D (secondary aim), and pain conditions in observational studies. DESIGN: Published observational research on 25(OH)D concentration and pain-related conditions was systematically searched for in electronic sources (MEDLINE, EMBASE and Cochrane Central Register of Controlled Trials) and a random-effects meta-analysis was conducted on included studies. RESULTS: Eighty-one observational studies with a total of 50 834 participants were identified. Compared with controls, mean 25(OH)D concentration was significantly lower in patients with arthritis (mean difference (MD): -12·34 nmol/l; P<0·001), muscle pain (MD: -8·97 nmol/l; P=0·003) and chronic widespread pain (MD: -7·77 nmol/l; P<0·001), but not in patients with headache or migraine (MD: -2·53 nmol/l; P=0·06). The odds of vitamin D deficiency was increased for arthritis, muscle pain and chronic widespread pain, but not for headache or migraine, compared with controls. Sensitivity analyses revealed similar results. CONCLUSIONS: A significantly lower 25(OH)D concentration was observed in patients with arthritis, muscle pain and chronic widespread pain, compared with those without. These results suggest that low 25(OH)D concentrations may be associated with pain conditions.

Monthly vitamin D supplementation, pain, and pattern of analgesic prescription: secondary analysis from the randomized, double-blind, placebo-controlled Vitamin D Assessment study.

Observational studies suggest that vitamin D deficiency is associated with higher risk of pain. However, evidence on the effect of vitamin D supplementation on pain is limited and contradictory. The aim of this study was to compare the effect of monthly high-dose vitamin D supplementation on a pain impact questionnaire (PIQ-6) score and prescription of analgesics in the general population. We performed a randomized, double-blind, placebo-controlled trial of 5108 community-dwelling participants, aged 50 to 84 years, who were randomly assigned to receive monthly 100,000-IU capsules of vitamin D3 (n = 2558) or placebo (n = 2550) for a median of 3.3 years. The PIQ-6 was administered at baseline, year 1, and final follow-up. Analgesic prescription data were collected from Ministry of Health. There was no difference in mean PIQ-6 score at the end of follow-up (adjusted mean difference: 0.06; P = 0.82) between the vitamin D (n = 2041) and placebo (n = 2014) participants. The proportion of participants dispensed one or more opioids was similar in the vitamin D group (n = 559, 21.9%) compared with placebo (n = 593, 23.3%); the relative risk (RR) adjusted for age, sex, and ethnicity was 0.94 (P = 0.24). Similar results were observed for dispensing of nonsteroidal anti-inflammatory drugs (RR = 0.94; P = 0.24) and other nonopioids (RR = 0.98; P = 0.34). Focusing on vitamin D deficient participants (<50 nmol/L, 24.9%), there was a lower risk of dispensing nonsteroidal anti-inflammatory drugs in the vitamin D group compared with placebo (RR = 0.87; P = 0.009); all other subgroup analyses were not significant. Long-term monthly high-dose vitamin D supplementation did not improve mean PIQ-6 score or reduce analgesic dispensing in the general population.

Noncalcemic adverse effects and withdrawals in randomized controlled trials of long-term vitamin D2 or D3 supplementation: a systematic review and meta-analysis.

CONTEXT: Recent randomized controlled trials (RCTs) provide evidence for a possible beneficial impact of vitamin D supplementation on health outcomes beyond bone health, but there are few reviews of noncalcemic adverse effects from long-term supplementation. OBJECTIVE: The aims of this systematic review of vitamin D supplementation in RCTs were as follows: to determine whether all adverse effects, when combined, are reported equally between treatment arms; to identify the most common noncalcemic adverse effects reported; and to ascertain whether withdrawal rates, as a marker of clinical adverse effects, differ between treatment arms. DATA SOURCES: The MEDLINE Ovid, Embase, and Cochrane Library databases were searched systematically up to May 2016. STUDY SELECTION: Randomized controlled trials that met the following criteria were selected: administered vitamin D2 or D3 supplements for a minimum supplementation or follow-up period of 24 weeks, had a placebo/control group, and were conducted among adults (≥ 18 y). DATA EXTRACTION: Two researchers independently screened studies for eligibility, extracted data, and carried out quality assessment of selected studies. A total of 128 studies with 52 297 participants were identified. A random-effects model was used to calculate risk ratios in a meta-analysis. RESULTS: Long-term vitamin D2 or D3 supplementation, compared with placebo, did not increase all adverse effects, when combined, as reported in 62 studies with 19 389 participants (relative risk [RR] = 0.97; 95%CI, 0.92-1.02). Vitamin D also did not increase the risk of the most common noncalcemic adverse effects: gastrointestinal symptoms were reported in 27 studies with 9189 participants (RR = 1.01; 95%CI, 0.87-1.17), and dermatological symptoms were reported in 8 studies with 1695 participants (RR = 1.33; 95%CI, 0.82-2.15). Vitamin D did not increase withdrawals from 123 studies with 41 861 participants (RR = 1.03; 95%CI, 0.96-1.09). However, participants given vitamin D were more likely to report withdrawals than those given placebo in studies in which calcium was given in both arms (RR = 1.16; 95%CI, 1.02-1.33) when compared with participants in studies in which calcium was not given in either arm (RR = 1.00; 95%CI, 0.95-1.06; P for interaction = 0.009). CONCLUSIONS: Overall, these findings suggest that vitamin D, by itself, does not increase the risk of noncalcemic adverse effects.

Effect of Vitamin D Supplementation on Pain: A Systematic Review and Meta-analysis.

BACKGROUND: There is conflicting evidence from previous qualitative reviews on the effect of vitamin D supplementation on pain. OBJECTIVE: To determine with quantitative methods if vitamin D supplementation lowers pain levels. STUDY DESIGN: Quantitative meta-analysis of published randomized controlled trials (RCTs). SETTING: This meta-analysis examined all studies involving the effect of vitamin D supplementation on pain score. METHOD: Electronic sources (Medline, Embase, Cochrane Central Register of Controlled Trials, clinical trials website, and Google scholar) were systematically searched for RCTs of vitamin D supplementation and pain from inception of each database to October 2015. RESULTS: Nineteen RCTs with 3,436 participants (1,780 on vitamin D supplementation and 1,656 on placebo) were included in the meta-analysis. For the primary outcome (mean change in pain score from baseline to final follow-up), 8 trials with 1,222 participants on vitamin D and 1,235 on placebo reported a significantly greater mean decrease in pain score for the vitamin D group compared to placebo (mean difference -0.57, 95% CI: -1.00 to -0.15, P = 0.007). The effect from vitamin D was greater in patients recruited with pre-existing pain (P-value for interaction = 0.03). Fourteen studies (1,548 on vitamin D, 1,430 on placebo) reported the mean pain score at final follow-up outcome, and no statistical difference was observed (mean difference -0.06, 95%CI: -0.44 to 0.33, P = 0.78). In 4 studies which reported pain improvement (209 on vitamin D, 146 on placebo), the effect size although not significant, shows participants in the vitamin D supplementation group were more likely to report pain improvement compared with the placebo group (relative risk 1.38, 95%CI: 0.93 to 2.05, P = 0.11). LIMITATIONS: Only a few studies reported the mean score change from baseline to final follow-up, and we do not have enough data to determine any modifying effect of baseline vitamin D status and different doses of vitamin D supplementation on pain. CONCLUSION: A significantly greater mean decrease in pain score (primary outcome) was observed with vitamin D supplementation compared with placebo in people with chronic pain. These results suggest that vitamin D supplementation could have a role in the management of chronic pain. KEY WORDS: Meta-analysis, pain, randomized controlled trials, vitamin D supplementation.

Hypercalcemia, hypercalciuria, and kidney stones in long-term studies of vitamin D supplementation: a systematic review and meta-analysis.

BACKGROUND: Vitamin D supplementation is increasingly being used in higher doses in randomized controlled trials (RCTs). However, adverse events from very large annual doses of vitamin D have been shown in 2 RCTs, whereas in a third RCT, low-dose vitamin D, with calcium supplements, was shown to increase kidney stone risk. OBJECTIVE: We analyzed the side effects related to calcium metabolism in RCTs, specifically hypercalcemia, hypercalciuria, and kidney stones, in participants who were given vitamin D supplements for ≥24 wk compared with in subjects in the placebo arm. DESIGN: The following 3 main online databases were searched: Ovid Medline (PubMed), EMBASE, and the Cochrane Library. Software was used for the meta-analysis. RESULTS: A total of 48 studies with 19,833 participants were identified, which reported ≥1 of the following side effects: hypercalcemia, hypercalciuria, or kidney stones. Of these studies, kidney stones were reported in only 9 trials with a tendency for fewer subjects reporting stones in the vitamin D arm than in the placebo arm (RR: 0.66, 95% CI: 0.41, 1.09; P = 0.10). In 37 studies, hypercalcemia was shown with increased risk shown for the vitamin D group (RR: 1.54; 95% CI: 1.09, 2.18; P = 0.01). Similar increased risk of hypercalciuria was shown in 14 studies for the vitamin D group (RR: 1.64; 95% CI: 1.06, 2.53; P = 0.03). In subgroup analyses, it was shown that the effect of vitamin D supplementation on risk of hypercalcemia, hypercalciuria, or kidney stones was not modified by baseline 25-hydroxyvitamin D, vitamin D dose and duration, or calcium co-supplementation. CONCLUSIONS: Long-term vitamin D supplementation resulted in increased risks of hypercalcemia and hypercalciuria, which were not dose related. However, vitamin D supplementation did not increase risk of kidney stones. Additional large RCTs of long-term vitamin D supplementation are required to confirm these findings.