Medically reviewed on July 11, 2023 by Jordan Stachel, M.S., RDN, CPT. To give you technically accurate, evidence-based information, content published on the Everlywell blog is reviewed by credentialed professionals with expertise in medical and bioscience fields.
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Digestion—the process in which the body breaks down food to deliver nutrients, vitamins, and minerals to the body—is critical to growth, cell repair, and energy production.  Maintaining a healthy gut microbiome is essential to maintaining gastrointestinal health and supporting overall well-being.
If you’re looking for tips on how to speed up digestion, there are several vitamins for digestion that can promote better nutrient absorption and support gut health.
1. Vitamin C
Vitamin C is typically associated with the immune system. It works to boost the immune response by supporting the function and activity of various immune cells. As an antioxidant, vitamin C aids in the neutralization of free radicals, which can harm immune cells and limit their capacity to fight infections. It also promotes the production of white blood cells such as lymphocytes and phagocytes, which can also help fight against infections. 
However, the benefits of vitamin C extend beyond immune function.
Vitamin C is also believed to shift the bacterial populations within the gut, producing anti-inflammatory effects that may contribute to improved gut health. More specifically, it may increase good bacteria and decrease bad bacteria. 
This can aid those with inflammatory bowel disease (IBD), a condition that involves chronic inflammation of the gastrointestinal tract and includes Crohn’s disease and ulcerative colitis. 
Vitamin C supplements are widely available; however, you can also find vitamin C in fruits and vegetables, such as: 
- Citrus, including oranges, kiwi, lemon, and grapefruit
- Bell peppers
- Brussels sprouts
- White potatoes
If you choose to take a vitamin C supplement, know that the daily recommended dose is 90 milligrams per day for men and 75 milligrams per day for women. The Tolerable Upper Intake Level (UL) differs, however, and refers to the maximum daily intake that’s unlikely to adversely affect overall health. For vitamin C, the UL is 2,000 milligrams per day. 
If you’re not consuming enough vitamin C in your regular diet, a deficiency may manifest as fatigue, malaise, and, in extreme cases, scurvy.5 That said, too much vitamin C—often as a result of taking too many vitamin C supplements, rather than intaking an excess of vitamin C-rich foods—can cause digestive distress like nausea, diarrhea, and acid reflux. 
2. Vitamin D
We can absorb vitamin D from the sun, as well as digestive supplements and food like fatty fish, fish oils, egg yolks, cheese, and beef liver. It plays a critical role in immune responses and the formation of bones since it helps the body absorb calcium and phosphorus. It may also help regulate inflammation throughout the body, including within the digestive system. 
Its role in gastrointestinal inflammation lies in its ability to affect the microbiome and ease IBD conditions, similar to vitamin C. It’s believed that IBD occurs as a result of an insufficient immune response to antigens (toxic or foreign invaders) within the gastrointestinal tract. Vitamin D may help decrease the prevalence and/or risk of developing IBD by supporting immune function and easing its symptoms, such as inflammation. 
A study also found that vitamin D can regulate calcium absorption within the intestine, supporting calcium-necessary processes such as: 
- Muscle movement
- Nerve messages from the brain to the body
It’s recommended that adults take 600 international units (IU) of vitamin D daily. Although those over 70 years of age should have 800 IU daily. The UL for vitamin D is 4,000 IU per day. 
3. Vitamin A
Vitamin A plays a role in vision, bone health, reproductive health, and immune function.  A vitamin A deficiency is often associated with gastrointestinal diseases.
While a lack of vitamin A does not cause these conditions, celiac disease, Crohn’s disease, cirrhosis, alcoholism, and cystic fibrosis can lead to vitamin A malabsorption. Vitamin A insufficiency can exacerbate the imbalance between the creation and elimination of free radicals within the intestinal mucus lining of individuals with Crohn's disease. 
That said, vitamin A toxicity is far more common than insufficiencies and can lead to vision changes, bone pain, nausea, vomiting, and dry skin. To avoid these symptoms, it’s important to stay within the daily limits: 900 micrograms for men and 700 micrograms for women. Toxicity levels lie beyond 3,000 micrograms per day. 
Vitamin A supplements are available to support gastrointestinal health; you can also find it in some of the best foods for digestion, including: 
- Herring and salmon
- Beef liver
- Green leafy vegetables
- Sweet potatoes
- Winter squash
4. B Vitamins
B vitamins are essential to overall health and play a role in red blood cell and energy production. More specifically, they help release energy by breaking down carbohydrates and fats.  B vitamins for digestion include:
- B1 (Thiamine) – Thiamine helps the body produce hydrochloric acid, which is essential for proper stomach acid secretion. Adequate stomach acid is crucial for the breakdown of food and optimal nutrient absorption.13 Good food sources of thiamine include whole grains (such as brown rice and oats), legumes, nuts, and pork. The recommended daily intake for thiamine varies by age and sex, but for adults, it typically ranges from 1.2 to 1.4 milligrams daily. There is no established upper limit for thiamine as it’s considered safe, even at high doses. 
- B2 (Riboflavin) – Riboflavin is essential for the metabolism of macronutrients (carbohydrates, proteins, and fats) that you consume in your diet. It also acts as an antioxidant and helps neutralize free radicals, reducing oxidative stress and potential damage to cells and tissues in the digestive system.15 It’s found in meat and fortified foods, as well as nuts, green vegetables, and dairy. Men should have 1.3 milligrams daily, while women should have 1.1 milligrams daily. There is no established UL. 
- B3 (Niacin) – Niacin plays a role in the metabolism of carbohydrates, proteins, and fats, supporting the energy production process. Additionally, it aids in maintaining the health of the digestive tract lining.  Foods rich in niacin include meat (poultry, fish, beef), nuts, whole grains, and legumes. The recommended daily intake for niacin in men is 16 milligrams; for women it's 14 milligrams. The upper limit for niacin for digestive supplements is set at 35 milligrams per day to prevent potential adverse effects. 
- B6 (Pyridoxine) – Pyridoxine plays a vital role in breaking down proteins and supporting the metabolism of amino acids in the digestive process. It also aids in the synthesis of neurotransmitters that influence gut function.19 Foods high in vitamin B6 include beef liver, tuna, salmon, fortified cereals, chickpeas, poultry, and fruits and vegetables like leafy greens, bananas, papayas, oranges, and cantaloupe. The recommended daily amount varies by age, but dosages for men range from 1.3 to 1.7 milligrams. For women, dosages range from 1.2 to 2.0 milligrams, depending on age and pregnancy status. The UL is 100 milligrams daily. 
- B7 (Biotin) – Biotin supports the breakdown of carbohydrates, proteins, and fats, helping to convert food into energy. It also contributes to maintaining the health of the intestinal lining.21 Biotin is found in foods such as eggs, nuts, seeds, sweet potatoes, and fish like salmon. Adults should have 30 micrograms daily, while those who are breastfeeding should increase their intake to 35 micrograms per day. Biotin does not have a UL as it’s unlikely to cause adverse health effects. 
- B12 (Cobalamin) – Vitamin B12 is crucial for the formation of red blood cells and nerve function, but it also aids in the breakdown of fatty acids and amino acids during normal digestion. Adequate B12 is also necessary for maintaining a healthy gastrointestinal tract. Foods containing vitamin B12 include meat, fish, poultry, dairy products, fortified cereals, tempeh, strawberries, and beans.23 Adults should have 2.4 micrograms daily, and there is no established upper limit. However, supplements with more than 25 micrograms of B12 may interact with bone density. 
What About Probiotics?
In addition to vitamins, daily probiotics can also help aid healthy digestion and promote gut health. These microorganisms primarily consist of various strains of good bacteria, such as Lactobacillus and Bifidobacterium, and some yeasts. They can help to: 
- Restore gut microbiome balance
- Enhance nutrient absorption
- Support immune function
- Reinforce the gut’s protective barrier
Research suggests that probiotics may help manage conditions such as irritable bowel syndrome (IBS), inflammatory bowel disease (IBD), and antibiotic-associated diarrhea. They can also alleviate digestive symptoms like bloating, gas, and discomfort. 
As an added bonus to potential gut benefits, probiotics may also benefit the brain. The gut and brain are connected through the gut-brain axis, a bidirectional communication system. Probiotics can influence this axis to positively impact mood, stress levels, and cognitive function. More specifically, they produce certain neurotransmitters that play a role in regulating mood and emotional well-being. 
To consume more probiotics, seek out probiotic-rich foods such as kefir, yogurt, sauerkraut, miso, and kimchi. Additionally, probiotic supplements are available, which can provide specific strains in concentrated forms.
See related: Why Do I Bloat After Eating?
Support Your Digestive Health With Everlywell
Vitamins C, D, A, and B can play integral roles in your nutritional digestive health. Fortunately, they’re available in various foods and as supplements to ensure you’re getting enough to support full-body wellness.
To determine whether you’re getting adequate levels of each vitamin, Everlywell provides at-home lab tests to assess your nutritional health and food sensitivity.
These include the at-home Vitamin D Test. We also provide vitamin-based supplements, including Vitamin B12, Vitamin B6, and Vitamin D3. If you’re looking for a full spectrum of nutritional coverage, opt for the Multivitamin Gummy which includes vitamins A, B5, B6, B12, C, D, E, folate, iodine, and zinc.
- NIDDK. Your Digestive System & How It Works. NIDDK. URL. Published May 11, 2023.
- Carr AC, Maggini S. Vitamin C and immune function. Nutrients. 2017;9(11):1211. URL.
- Otten AT, Bourgonje AR, Peters V, Alizadeh BZ, Dijkstra G, Harmsen HJM. Vitamin C Supplementation in Healthy Individuals Leads to Shifts of Bacterial Populations in the Gut—A Pilot Study. Antioxidants. 2021;10(8):1278. doi:https://doi.org/10.3390/antiox10081278. URL.
- CDC - Home Page - Inflammatory Bowel Disease (IBD) - Division of Population Health. Centers for Disease Control and Prevention. URL. Published 2019.
- Harvard School of Public Health. Vitamin C. The Nutrition Source. URL. Published March 2020.
- Sestili MA. Possible adverse health effects of vitamin C and ascorbic acid. Seminars in Oncology. 1983;10(3):299-304. URL. Accessed July 29, 2023.
- Harvard School of Public Health. Vitamin D. The Nutrition Source. URL. Published July 2, 2019.
- Tabatabaeizadeh SA, Tafazoli N, Ferns GA, Avan A, Ghayour-Mobarhan M. Vitamin D, the gut microbiome and inflammatory bowel disease. Journal of Research in Medical Sciences : The Official Journal of Isfahan University of Medical Sciences. 2018;23. doi:https://doi.org/10.4103/jrms.JRMS_606_17. URL.
- Li S, De J, Hutchens S, et al. Analysis of 1,25-Dihydroxyvitamin D 3 Genomic Action Reveals Calcium-Regulating and Calcium-Independent Effects in Mouse Intestine and Human Enteroids. 2020;41(1). doi:https://doi.org/10.1128/mcb.00372-20. URL.
- National Institutes of Health. Office of Dietary Supplements - Vitamin A. Nih.gov. URL. Published January 14, 2021.
- Harvard School of Public Health. Vitamin A. The Nutrition Source. URL. Published July 2, 2019.
- Harvard School of Public Health. B Vitamins. The Nutrition Source. URL. Published June 4, 2019.
- Levin LG, Mal’tsev GI, Gapparov MM. [Effect of thiamine deficiency in hydrochloric acid secretion in the stomach]. Voprosy Pitaniia. 1978;(5):36-40. URL.
- Harvard T.H. Chan. Thiamin – Vitamin B1. The Nutrition Source. URL. Published July 8, 2019.
- Navid Mahabadi, Aakriti Bhusal, Banks SW. Riboflavin Deficiency. Nih.gov. URL. Published July 3, 2019.
- Harvard T.H. Chan. Riboflavin – Vitamin B2. The Nutrition Source. URL. Published July 24, 2020.
- National Institutes of Health. Office of Dietary Supplements - Niacin. Nih.gov. URL. Published 2017.
- Harvard School of Public Health. Niacin – Vitamin B3. The Nutrition Source. URL. Published July 6, 2020.
- Parra M, Stahl S, Hellmann H. Vitamin B6 and Its Role in Cell Metabolism and Physiology. Cells. 2018;7(7):84. doi:https://doi.org/10.3390/cells7070084. URL.
- Harvard School of Public Health. Vitamin B6. The Nutrition Source. URL. Published June 4, 2019.
- Office of Dietary Supplements - Biotin. Nih.gov. URL. Published 2017.
- Harvard School of Public Health. Biotin – Vitamin B7. The Nutrition Source. URL. Published July 24, 2019.
- National Institutes of Health. Office of Dietary Supplements - Vitamin B12. Nih.gov. URL. Published March 9, 2022.
- Harvard School of Public Health. Vitamin B12. The Nutrition Source. URL. Published June 4, 2019.
- Hemarajata P, Versalovic J. Effects of probiotics on gut microbiota: mechanisms of intestinal immunomodulation and neuromodulation. Therapeutic Advances in Gastroenterology. 2012;6(1):39-51. doi:https://doi.org/10.1177/1756283x12459294 URL.
- Satish Kumar L, Pugalenthi LS, Ahmad M, Reddy S, Barkhane Z, Elmadi J. Probiotics in Irritable Bowel Syndrome: a Review of Their Therapeutic Role. Cureus. 2022;14(4). doi:https://doi.org/10.7759/cureus.24240. URL.
- Appleton J. The Gut-Brain Axis: Influence of Microbiota on Mood and Mental Health. Integrative Medicine: A Clinician’s Journal. 2018;17(4):28-32. URL.