Should you take vitamin D supplements?

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1. 1

   Vitamin D Supplements and Prevention of Cancer and Cardiovascular Disease

   New England Journal of Medicine (Manson et al.)Published Nov 10, 2018Checked Sep 30, 2026

   “A total of 25,871 participants, including 5106 black participants, underwent randomization. Supplementation with vitamin D was not associated with a lower risk of either of the primary end points. During a median follow-up of 5.3 years, cancer was diagnosed in 1617 participants (793 in the vitamin D group and 824 in the placebo group; hazard ratio, 0.96; 95% confidence interval [CI], 0.88 to 1.06; P=0.47). A major cardiovascular event occurred in 805 participants (396 in the vitamin D group and 409 in the placebo group; hazard ratio, 0.97; 95% CI, 0.85 to 1.12; P=0.69). Supplementation with vitamin D did not result in a lower incidence of invasive cancer or cardiovascular events than placebo. (Funded by the National Institutes of Health and others; VITAL ClinicalTrials.gov number, NCT01169259 .).”

2. 2

   The D-Health Trial: a randomised controlled trial of the effect of vitamin D on mortality

   The Lancet Diabetes & Endocrinology (Neale et al.)Published Jan 10, 2022Checked Sep 30, 2026

   “In the D-Health trial, 21,315 Australians aged 60–84 took 60,000 IU of vitamin D or placebo monthly for up to five years. Vitamin D did not reduce all-cause mortality.”

3. 3

   Effects of vitamin D supplementation on musculoskeletal health: a systematic review, meta-analysis, and trial sequential analysis

   The Lancet Diabetes & Endocrinology (Bolland et al.)Published Oct 4, 2018Checked Sep 30, 2026

   “A meta-analysis of 81 randomised trials found that vitamin D supplementation does not prevent fractures or falls, or have clinically meaningful effects on bone mineral density. There is little justification for supplements to maintain or improve musculoskeletal health, except for rare conditions.”

4. 4

   From Routine Supplementation to Targeted Repletion: Vitamin D Deficiency in UVB-Constrained, Pollution-Exposed, and Ageing Populations-Musculoskeletal and Extra-Skeletal Perspectives.

   Nutrients (Yoon et al.)Published Aug 21, 2026Checked Oct 4, 2026

   “Key Findings: The strongest rationale for vitamin D repletion remains musculoskeletal, particularly for osteomalacia, muscle function, osteoporosis care, and fracture-related vulnerability in deficient or high-risk patients. Management should separate generally healthy adults from patients with an indication for testing or treatment. Historical and regional expert frameworks describe time-limited higher-dose repletion for documented deficiency, but these regimens should not be interpreted as a current universal Endocrine Society treatment standard. Short-term trials using moderate cumulative oral doses suggest broadly comparable biochemical repletion with daily, weekly, or monthly schedules; equivalence has not been established for long-term clinical outcomes, frail populations, or large intermittent doses. Extra-skeletal associations remain less trial-supported. Vitamin D deficiency should be managed using clinically indicated assessment, explicit repletion and maintenance regimens, and selective biochemical reassessment. Targets above conventional skeletal adequacy thresholds remain investigational and should not be applied as universal treatment goals.”

5. 5

   Micronutrients in Cardiovascular Disease: A Comprehensive Review of Vitamins, Trace Minerals, and Electrolytes.

   Nigerian medical journal : journal of the Nigeria Medical Association (Iyidobi et al.)Published Sep 14, 2026Checked Oct 4, 2026

   “PubMed, Scopus, Cochrane Library, and Google Scholar were searched (1980-2024) for English-language human studies on micronutrients and cardiovascular outcomes. Study selection involved screening, full-text review, and snowballing. Quality was assessed through critical appraisal. Data were synthesised thematically. Approximately 70 key studies were included from over 200 identified references. Antioxidant vitamins show inconsistent benefits, with some cohorts demonstrating 27-47% risk reductions despite null RCT results. Vitamin D deficiency (30-50% prevalence) is consistently associated with CVD risk, though supplementation trials are mixed. B-vitamins improve endothelial function via homocysteine reduction. Trace minerals demonstrate biphasic relationships, where both deficiency and overload increase CVD risk. Electrolyte balance, particularly the sodium-potassium ratio, critically determines blood pressure and cardiovascular outcomes. Current evidence does not support universal supplementation. The complex relationships between micronutrient status and CVD outcomes underscore the need for personalized approaches.”

6. 6

   Beyond Bone Health: Exploring the "Heart-Brain-Bone" Axis Modulated by Lipid-Soluble Nutrients (Omega-3, Vitamin D3, and Vitamin K2).

   Nutrients (Fang et al.)Published Aug 19, 2026Checked Oct 4, 2026

   “Recognized safety signals include a dose-dependent increase in atrial fibrillation with high-dose omega-3, adverse skeletal effects of high-dose or bolus vitamin D, and clinically relevant interference of even low-dose MK-7 with vitamin K antagonist therapy.ConclusionsNo adequately powered randomized trial has demonstrated that the combination of long-chain omega-3, vitamin D3 and MK-7 is superior to its individual components or to placebo for any clinical endpoint. The combined regimen is therefore mechanistically rational and hypothesis-generating rather than clinically established; benefit appears most plausible in individuals with elevated risk or demonstrable nutritional insufficiency, and least in replete, low-risk populations. Findings should be interpreted within a broader healthy-aging context that includes lifestyle and psychosocial factors. Adequately powered factorial randomized controlled trials stratified by baseline Omega-3 index, 25(OH)D and vitamin K status, with prespecified mechanistic biomarkers and hard endpoints, are required.”