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HEALTH

The Claim

A meta-analysis published in 2023 found that taking 3,200 to 4,000 International Units (IU) of vitamin D daily is associated with a higher risk of hypercalcemia.

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The Short Version

The cited 2023 meta-analysis did report that long-term vitamin D supplementation at 3,200-4,000 IU/day was associated with a higher risk of hypercalcemia. The pooled estimate showed a statistically significant increase versus control. Important context is that the absolute excess risk was small and reported cases were often asymptomatic or reversible.

Caveats

  • The finding is about a relative increase in risk; the absolute increase was small, roughly a few extra cases per 1,000 people.
  • This does not mean everyone taking 3,200-4,000 IU/day will develop hypercalcemia, and some individual trials found no increase in specific populations.
  • The claim reflects what the meta-analysis found, not necessarily a large or clinically severe danger in all users.

The Receipts

  1. Long-term supplementation with 3200 to 4000 IU of vitamin D daily and adverse events: a systematic review and meta-analysis of randomized controlled trials

    PMC

  2. Long-term supplementation with 3200 to 4000 IU of vitamin D daily and adverse events: a systematic review and meta-analysis of randomized controlled trials

    PubMed

  3. Long-term supplementation with 3200 to 4000 IU of vitamin D daily and adverse events: a systematic review and meta-analysis of randomized controlled trials

    PubMed Central

  4. Search results for 3200 to 4000 IU vitamin D hypercalcemia meta-analysis

    PubMed

  5. Vitamin D Fact Sheet for Consumers

    National Institutes of Health Office of Dietary Supplements

  6. Cholecalciferol (vitamin D3): efficacy, safety, and implications in clinical practice

    Frontiers in Nutrition

  7. Safety of Long-term High-Dose Vitamin D Supplementation: An Updated Systematic Review

    PubMed

  8. Taking too much vitamin D can cloud its benefits and create health risks

    Harvard Health Publishing

  9. Safety and tolerability of high-dose daily vitamin D₃ in the Vitamin D and Type 2 Diabetes (D2d) study

    HealthPartners / European Journal of Clinical Nutrition (article PDF host)

  10. Long-term supplementation with 3200 to 4000 IU of vitamin D daily and adverse events: a systematic review and meta-analysis of randomized controlled trials

    European Journal of Nutrition (SpringerLink)

+ 6 more sources — see the full list on Lenz

Filed Under

HypercalcemiaVitamin D

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