Valproic Acid and Liver Protection: Investigating the Role of Vitamin U
By Julia Haimovich, Accredited Practising Dietitian.
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Valproic acid (VPA) is a commonly prescribed agent for neurological and psychiatric conditions such as epilepsy, bipolar disorder, and migraine prophylaxis. While highly effective, its clinical use is often limited by the risk of hepatotoxicity, which can range from mild liver enzyme elevations to rare cases of acute liver failure. Kadam et al. (2025) outlined the main mechanisms of VPA-induced liver injury, highlighting oxidative stress, impaired mitochondrial activity, and carnitine depletion as central drivers of hepatic toxicity [1]. Given these concerns, there is growing interest in natural compounds with potential hepatoprotective actions. One such compound is S-methylmethionine (SMM), more widely known as vitamin U. Though not technically classified as a vitamin, vitamin U has been studied for its gastrointestinal benefits and emerging role in supporting liver health [2].
Vitamin U is a methionine-derived compound abundant in cruciferous vegetables, including cabbage, broccoli, kale, Brussels sprouts, and spinach. First popularised in the 1950s, raw cabbage juice was found to accelerate healing in patients with peptic ulcers. Since then, research has expanded to its antioxidant, anti-inflammatory, and cytoprotective functions, especially in relation to gastrointestinal and hepatic systems [2]. Animal studies add further evidence. For instance, research on broiler chickens showed that dietary vitamin U improved liver function and enhanced intestinal barrier integrity, suggesting benefits for both digestive and metabolic health [4]. These outcomes support the idea that vitamin U promotes cellular resilience and tissue recovery in organs under stress.
Preclinical findings suggest vitamin U may protect the liver against VPA-related damage. In a notable study, Sokmen et al. (2012) demonstrated that vitamin U supplementation in rats reduced VPA-induced hepatocellular injury. The protective effect was linked to lower oxidative stress markers and preservation of normal liver structure and function [3]. Mechanistically, vitamin U appears to act by neutralising reactive oxygen species produced during VPA metabolism. It may also help stabilise mitochondrial activity and strengthen detoxification processes, thereby mitigating liver cell injury [1,3].
Vitamin U is naturally present in widely available foods, making it simple to incorporate into a balanced diet. Rich dietary sources include cabbage, broccoli, Brussels sprouts, kale, and spinach. Although supplements are available, consuming vitamin U through whole foods is considered the safest and most effective method. For individuals on VPA or other liver-stressing medications, dietary intake may provide additional support. However, any supplementation or significant diet changes should be guided by a healthcare professional to ensure compatibility with ongoing treatment.
Valproic acid continues to be an essential therapy for several chronic conditions, but its potential for liver toxicity requires careful management. Vitamin U, abundant in cruciferous vegetables, shows promise in reducing VPA-related liver injury through antioxidant and cytoprotective mechanisms. Animal models demonstrate that vitamin U not only limits liver damage but may also enhance gut health, indicating a broader systemic role [1,3,4]. While human clinical data remain limited, including vitamin U-rich foods in the diet represents a practical and safe adjunct strategy to support liver function in individuals receiving VPA therapy.
References
- Kadam R, Palkar M, Pingili RB. Mechanisms involved in the valproic acid-induced hepatotoxicity: a comprehensive review. Toxicol Mech Methods. 2025 Feb 6:1-16. doi: 10.1080/15376516.2025.2459176. PMID: 39871487.
- Clinical Education. The Use Of Vitamin U For Gastric Ulcer Recovery. https://www.clinicaleducation.org/resources/reviews/the-use-of-vitamin-u-for-gastric-ulcer-recovery/
- Sokmen B, Tunali S, Yanardag R. Effects of vitamin U (S-methyl methionine sulphonium chloride) on valproic acid induced liver injury in rats. Food Chem Toxicol. 2012;50(10):3562–6. doi:10.1016/j.fct.2012.07.056
- Al-Kassie GAM, Roshdy NM, El-Kholy MMS. Effects of Vitamin U on Live Performance and Intestinal Tract Integrity in Broilers. Int J Poult Sci. 2013;12(1):30–35.
