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THYROID FUNCTION

Nickel

Ni — Element #28

also known as Nickel chloride, Nickel sulfate, Nickel carbonyl (toxic)

Nickel is an ultratrace mineral for which essentiality in humans has not been definitively established. Animal studies show nickel deficiency impairs growth and reproduction, and nickel is a cofactor for urease enzymes in microorganisms and plants. In humans, nickel is present in trace amounts and may interact with iron metabolism, but a specific biological role has not been confirmed.

  • Animal and microbial evidence suggests nickel may be a cofactor for enzymes involved in hydrogen and methane metabolism
  • May influence iron absorption; animal data show nickel-deficient diets reduce iron utilization
  • Proposed to play an ancillary role in amino acid metabolism and membrane function — animal data only
  • No confirmed essential biological function in humans has been established

Active in Ni²⁺ (nickelous).

Tolerable Upper Intake Level (UL): 1.0 mg/day for adults (supplemental nickel)
Nickel is one of the most common contact allergens; nickel allergy affects approximately 10–15% of the population, causing allergic contact dermatitis
Dietary nickel can exacerbate systemic contact dermatitis in sensitized individuals; low-nickel diets are sometimes prescribed
Nickel carbonyl gas is extremely toxic and carcinogenic (occupational hazard); not relevant to dietary exposure
Nickel compounds are classified as Group 1 carcinogens (IARC) for specific occupational inhalation exposures — dietary nickel risk is not comparably established

NIH ODS — Nickel · NCBI — Nickel and Human Health Review · Britannica — Nickel

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The curious few.
50 founding spots left

Know what you're putting in your body.

158 herbs, nutrients, and compounds. What the science says, what tradition knew, and what to watch for. Founding members keep this running.

$60 /year

Founding rate — locked for life. Regular price after launch: $96/year.

  • ✓ Full access to all 158+ entries
  • ✓ Print-ready reference card for every herb
  • ✓ Monthly curated set — 5 herbs, one body system
  • ✓ The Sunday Letter — weekly research digest
  • ✓ Bookmarks synced across devices
  • ✓ Founding rate locked forever
Become a founding member

Cancel any time. No questions asked.