Essential trace mineral needed in small amounts for building bone, handling sugars and fats, and antioxidant defense. Most people eating a varied diet already get enough, so adding more is weakly supported. Its defining trait is a narrow safe window: too much builds up in the brain and harms movement. Best kept in balance, not pushed. (Full Review)

Protocol

Dose

1–5 mg/day

Modest amount within a multi-mineral bone formula, not stand-alone high-dose

Timing

With food

No circadian advantage; separate from high-dose iron

Frequency

Single daily dose

Splitting offers no advantage; large boluses discouraged

Time to effect

Deficiency correction

Weeks to a few months

Biochemical and connective-tissue abnormalities improve

Bone density

1–2 years

Within a multi-mineral regimen; not separable from other minerals

Benefits

Medium: Maintenance of bone mineral density and skeletal integrity; correction of deficiency-related metabolic and connective-tissue dysfunction

Low: Antioxidant defense via MnSOD support; lower type 2 diabetes risk associated with higher dietary intake

Speculative: Joint and cartilage support in osteoarthritis; wound healing and skin integrity

Contraindications

Chronic liver disease, cholestasis, or cirrhosis (advanced impairment, Child-Pugh Class B–C)

Long-term parenteral nutrition

SLC30A10 or SLC39A14 mutations or other manganese-handling disorders

Documented hypermanganesemia

Pregnancy (high-dose supplementation)

Infants and children (unless clinician-directed)

Key Interactions

Iron supplements (ferrous sulfate, ferrous bisglycinate)

Calcium, magnesium, and zinc supplements (calcium carbonate, magnesium oxide, zinc gluconate)

Antacids and proton-pump inhibitors (omeprazole, calcium-containing antacids)

Supplements with additive manganese load (multivitamins, bone formulas, glucosamine–chondroitin–manganese, greens powders)

High tea or supplemental "green" intake

Risk & Side Effects

High: Neurotoxicity and manganism from chronic overexposure

Medium: Accumulation with impaired biliary excretion or liver disease; elevated blood manganese and gestational diabetes risk

Low: Neurodevelopmental effects of early-life overexposure

Speculative: Cardiovascular and mortality signals at extremes of intake

Monitoring

Marker	Target	Why
Whole-blood manganese	~4–15 µg/L (lab-dependent)	Best practical marker of recent exposure and accumulation
Liver function panel (ALT, AST, bilirubin)	Within conventional normal limits	Screens for impaired biliary excretion, the key accumulation risk
Ferritin and iron studies	Ferritin ~40–70 ng/mL	Iron status drives manganese absorption via shared transporter
Bone mineral density (DEXA)	T-score above −1.0	Contextualizes any bone-related rationale for manganese-containing formulas

Cadence: Baseline before supplementing, ~3 months after starting, then every 6–12 months; reassess promptly if neurological symptoms or liver concerns arise

Qualitative Assessment

Movement and coordination — new tremor, stiffness, slowed movement, or gait change
Mood and cognition — new irritability, low mood, or concentration difficulty
Energy and general well-being
Skin, hair, and nail integrity

Manganese for Health & Longevity

Protocol

Benefits

Risk & Side Effects

Monitoring

Qualitative Assessment