Research
Hormonal
Vitamin D3 supplementation at 100 mcg (4000 IU)/day is safe for long-term use in adults, as it does not elevate plasma calcium levels.
Taking 4000 IU of Vitamin D3 daily is safe and does not raise calcium levels, even over long periods.
GoodSupportsHIGH confidence
There were no significant differences or changes in serum total or plasma ionized calcium concentrations, either over time, or between groups.
Why this rating
Randomized controlled trial with biochemical markers.
Source
Randomized comparison of the effects of the vitamin D3adequate intake versus 100 mcg (4000 IU) per day on biochemical responses and the wellbeing of patients
Reinhold Vieth et al. · Nutrition Journal · 2004
DOI 10.1186/1475-2891-3-8
rct · n=130Cited 219×
Read the paper DOI resolved against Crossref · corpus check 2026-06-10
Related findings · Hormonal
- Initial treatment for type 2 diabetes should be a combination of metformin and either an SGLT-2 inhibitor or a GLP-1 receptor agonist to achieve cardiorenal protection, rather than monotherapy or older agents like sulfonylureas.Strong
- For patients with specific monogenic obesity syndromes (leptin deficiency, POMC/PCSK1/LEPR mutations), targeted pharmacotherapy (recombinant leptin or setmelanotide) is highly effective and should be prioritized, unlike in polygenic obesity.Strong
- Continued weekly administration of 2.4 mg subcutaneous semaglutide prevents weight regain and promotes further weight loss in adults with overweight or obesity, whereas switching to placebo results in significant weight regain.Strong
This is one finding among thousands. Every one is graded and traced to its source, so you can see what the evidence actually supports. Browse the research →