Nutritional causes of tremor are underinvestigated in standard clinical practice. The neurological system has significant nutritional dependencies, and deficiencies in specific micronutrients produce well-characterised tremor syndromes. Identifying and correcting these deficiencies before attributing tremor to essential tremor or early Parkinson's disease is both good clinical practice and potentially transformative for the patient.
Magnesium: The Under-Diagnosed Deficiency
Magnesium is a cofactor for over 300 enzymatic reactions. Its role in neuromuscular function is particularly critical: magnesium competes with calcium at the neuromuscular junction, moderating muscle contraction. Deficiency shifts this balance toward calcium dominance, producing hyperexcitability characterised by muscle cramps, fasciculations, and tremor. Dietary surveys consistently find that 50 to 60% of adults over 50 in Western countries consume below the recommended daily intake. Standard serum magnesium measures do not reliably detect deficiency because serum levels are maintained at the expense of intracellular stores; red blood cell magnesium or 24-hour urine magnesium are more sensitive tests.
Clinical Magnesium Dosing and Sources
- Dietary sources: pumpkin seeds (156mg per 28g), dark chocolate (50mg per 28g), almonds (76mg per 28g), cooked spinach (78mg per 100g)
- Supplementation: magnesium glycinate or magnesium malate are better tolerated and absorbed than magnesium oxide; 300 to 400mg elemental magnesium daily
- Transdermal magnesium: some evidence supports absorption through magnesium bath salts; not a replacement for oral supplementation
- Magnesium citrate: effective but has a laxative effect at higher doses
Vitamin B1 (Thiamine)
Thiamine is essential for glucose metabolism in neurons. Deficiency produces Wernicke's encephalopathy at its extreme, but subclinical deficiency causing cerebellar tremor is less well recognised. Risk groups include adults with alcohol dependency, those taking diuretics chronically, and anyone eating a very restricted diet. The cerebellar tremor from thiamine deficiency is typically symmetrical and intention-based, and can be confused with essential tremor. Standard RBC thiamine testing is the most sensitive measure.
Vitamin B6 (Pyridoxine)
B6 toxicity (from excessive supplementation above 200mg per day) paradoxically causes a sensory neuropathy that can include tremor. At physiological doses, B6 supports dopamine synthesis from L-DOPA and is important for neurotransmitter production generally. Standard dietary intake is usually sufficient; supplementation should be at low doses (1.3 to 1.7mg daily) unless supervised.
Vitamin B12
B12 deficiency causes demyelination of posterior columns and corticospinal tracts. The resulting neurological picture may include sensory ataxia, which produces a gait tremor similar in character to cerebellar tremor. Methylcobalamin is the active neurological form and is preferred to cyanocobalamin for neurological indications.
Sources
- Rude RK, Shils ME. (2006). Magnesium. In: Shils ME, et al. (eds). Modern Nutrition in Health and Disease. Lippincott Williams and Wilkins, 223-247.
- Stabler SP. (2013). Vitamin B12 deficiency. New England Journal of Medicine, 368(2), 149-160.
- Zis P, et al. (2019). Treatment of neurological manifestations of gluten sensitivity and coeliac disease. Current Treatment Options in Neurology, 21(3), 10.