From the Research
High vitamin B12 toxicity is rare and typically doesn't require specific treatment as the body naturally eliminates excess water-soluble vitamins. The primary approach is to discontinue any B12 supplements or injections and identify any underlying causes. For those with kidney dysfunction who cannot properly excrete B12, temporary dialysis might be considered in severe cases. Dietary modification to reduce consumption of B12-rich foods like liver, shellfish, and fortified cereals may help normalize levels. Symptoms of B12 toxicity, which can include acne, rosacea, headaches, anxiety, and nausea, generally resolve once supplementation stops. In cases where B12 elevation is secondary to liver disease, blood disorders, or certain cancers, treating the underlying condition is essential, as seen in a case report where a patient developed toxicity induced by multiple high doses of vitamin B12 during pernicious anemia treatment 1. Unlike fat-soluble vitamins that accumulate in body tissues, B12 excess is difficult to achieve through diet alone, and most healthy individuals can tolerate doses far exceeding the recommended daily allowance without adverse effects. Regular monitoring of B12 levels may be recommended until they return to normal range. It's worth noting that the management of patients with neurological manifestations of vitamin B12 deficiency may require parenteral replacement, even if the serum vitamin B12 level appears to be normal 2. However, in the context of high B12 toxicity, the focus should be on discontinuing supplementation and addressing any underlying causes, rather than initiating treatment for deficiency. The most recent study on vitamin B12 deficiency and its treatment does not directly address toxicity but highlights the importance of proper diagnosis and management of deficiency 3. In general, the approach to high B12 toxicity should prioritize discontinuation of supplements, identification of underlying causes, and monitoring of B12 levels, as the body is capable of eliminating excess water-soluble vitamins, including vitamin B12 4.