The liver is the second largest organ in our body after the skin. The liver is a metabolic powerhouse, and it performs many functions to support the body’s immunity, digestion, detoxification, vitamin storage and others. I have discussed the detoxification role of the liver in a previous post (See “What is Detox?” ). Let’s check out the vitamins that a healthy liver needs or stores to carry out its function. Deficiencies in these vitamins are known to associate with liver diseases.

Folate

B vitamins are a group of water-soluble vitamins necessary for healthy growth and metabolism. Among the B-vitamins, folate (or sometimes called B9) plays an essential role in many biochemical reaction reactions including methylation and metabolisms of sulphur-containing amino acids. The liver is the primary organ responsible for the storage and metabolism of folates. Low folate level is found to associate with liver diseases such as non-alcoholic fatty liver, liver damage, and liver cancer [1,2].

Folate is found naturally in foods. As folate is stored in the liver, animal livers are traditionally considered a good source of folate. However, many plant-based foods, including soybean, lentils, peas, kidney beans, artichoke, broccoli, asparagus, spinach, and avocados, are also rich in folate [3].  Hence, if you eat a variety of vegetables and legumes, you will be ensured of sufficient intake of folate.

Vitamin B12

Vitamin B12, or cobalamins, is another B-vitamin that is stored in the liver. Together with folate, B12 is needed for the formation and maturation of red blood cells. It is also used for the synthesis of DNA (deoxyribonucleic acid) and maintaining healthy nerves function [4]. Low level of B12 is also associated with many liver diseases [5,6].

The body is not able to produce vitamin B12. B12 is naturally found in animal products, including fish, meat, poultry, eggs, milk, and milk products [4]. For Lacto Ovo vegetarian, the egg is an essential source for vitamin B12. For vegan, it is crucial to include seaweeds fermented food in the diet. Even in animals, B12 is not produced by the host directly but by the gut bacteria. The fermentation process in foods such as tempeh, fermented beans, sauerkraut, natto, etc., helps to increase their B12 content [7]. Vegan should also consider taking B12 supplement once in a while.

Carotenoids

Carotenoids are the pigments in plants which produce bright yellow, red, and orange colours in fruits and vegetables.  Lycopene, beta-carotene, lutein, zeaxanthin, and beta-cryptoxanthin are examples of carotenoids.  Beta-carotene is a pro-vitamin A as it can be converted to vitamin A in the body. During the liver detoxification process, free radicals are released. Carotenoids are essential antioxidants that bind to these free radicals and help to reduce cellular damage in the liver. Increased intake of carotenoids can significantly reduce the risk of suffering from liver diseases [8]. Carotenoids are widely available in fruits and vegetables of different colours, so make sure you take a variety of them.

Vitamin D

Vitamin D is a fat-soluble hormone better known for bone health. However, the role of vitamin D to maintain a healthy liver is also no less important. Vitamin D can be generated from skin exposure to sunlight which produces pre-vitamin D3. The liver, together with the kidney, are involved in converting the pre-vitamin D3 into the physiologically active form of vitamin D (1,25 dihydroxyvitamin D) that can be utilised by the body. Vitamin D is found to be able to improve liver health in many ways. For example, it has an antiviral effect against hepatitis C virus. It also helps to reduce inflammation in the liver [9].

Food sources rich in Vitamin D include fatty fish, milk and cereals fortified with vitamin D, egg, cheese [10]. For vegan, sunlight treated mushrooms can be a good source [11]. Of course, you can always rely on exposing your skin under the sun to generate this crucial ingredient of health.      

Vitamin E

Vitamin E is a fat-soluble antioxidant. Its primary role in the liver is to protect the liver cells from oxidative damage that can lead to cell death and formation of scarred tissues in the liver. Vitamin E is now commonly used to treat and prevent the progression of non-alcoholic fatty liver [12]. 

Vitamin E is commonly found in vegetable oils such as sunflower oil, rice bran oil, and olive oil. It is also available in nuts (almond, peanut, walnut, etc.) and seeds (pumpkin and sunflower). Green leafy vegetables such as spinach and kale also contain a fair amount of vitamin D.

Conclusion

The liver is a storage place for excess vitamin B12 and folate, which are essential nutrients facilitating the formation and maturation of red blood cells. Liver diseases are commonly associated with a deficiency in vitamin B12 and folate. The liver also plays a vital role in converting pre-vitamin D3 to the physiologically active 1,25 dihyroxyvitamin D needed for bone, immune system, and liver health. Carotenoids and vitamin E are antioxidants that protect the liver cells from free radicals, the by-products of the liver detoxification process. They are needed to prevent liver damage.

References

[1]        V. Sid, Y.L. Siow, K. O, Role of folate in nonalcoholic fatty liver disease, Can. J. Physiol. Pharmacol. 95 (2017) 1141–1148. doi:10.1139/cjpp-2016-0681.

[2]        T.M. Welzel, H.A. Katki, L.C. Sakoda, A.A. Evans, W.T. London, G. Chen, S. O'Broin, F.-M. Shen, W.-Y. Lin, K.A. McGlynn, Blood Folate Levels and Risk of Liver Damage and Hepatocellular Carcinoma in a Prospective High-Risk Cohort, Cancer Epidemiol. Biomarkers &Amp; Prev. 16 (2007) 1279 LP – 1282. doi:10.1158/1055-9965.EPI-06-0853.

[3]        Folate — Health Professional Fact Sheet, (n.d.). https://ods.od.nih.gov/factsheets/Folate-HealthProfessional/ (accessed November 11, 2019).

[4]        H. Osiecki, The Nutrient Bible, 9th Ed., BioConcepts Publishing, Eagle Farm, OLD, Australia, 2014.

[5]        M. Mahamid, N. Mahroum, N.L. Bragazzi, K. Shalaata, Y. Yavne, M. Adawi, H. Amital, A. Watad, Folate and B12 Levels Correlate with Histological Severity in NASH Patients, Nutrients. 10 (2018) 440. doi:10.3390/nu10040440.

[6]        C. Fernández-Rodríguez, E. González-Reimers, G. Quintero-Platt, M.J. de la Vega-Prieto, O. Pérez-Hernández, C. Martín-González, E. Espelosín-Ortega, L. Romero-Acevedo, F. Santolaria-Fernández, Homocysteine, Liver Function Derangement and Brain Atrophy in Alcoholics, Alcohol Alcohol. 51 (2016) 691–697. doi:10.1093/alcalc/agw031.

[7]        F. Watanabe, Y. Yabuta, T. Bito, F. Teng, Vitamin B₁₂-containing plant food sources for vegetarians, Nutrients. 6 (2014) 1861–1873. doi:10.3390/nu6051861.

[8]        L.I. Elvira-Torales, J. García-Alonso, M.J. Periago-Castón, Nutritional Importance of Carotenoids and Their Effect on Liver Health: A Review., Antioxidants (Basel, Switzerland). 8 (2019). doi:10.3390/antiox8070229.

[9]        J.T. Keane, H. Elangovan, R.A. Stokes, J.E. Gunton, Vitamin D and the Liver-Correlation or Cause?, Nutrients. 10 (2018) 496. doi:10.3390/nu10040496.

[10]      Vitamin D — Health Professional Fact Sheet, (n.d.). https://ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/#h3 (accessed November 11, 2019).

[11]      G. Cardwell, J.F. Bornman, A.P. James, L.J. Black, A Review of Mushrooms as a Potential Source of Dietary Vitamin D, Nutrients. 10 (2018) 1498. doi:10.3390/nu10101498.

[12]      B.J. Perumpail, A.A. Li, N. John, S. Sallam, N.D. Shah, W. Kwong, G. Cholankeril, D. Kim, A. Ahmed, The Role of Vitamin E in the Treatment of NAFLD, Dis. (Basel, Switzerland). 6 (2018) 86. doi:10.3390/diseases6040086.