Hydrochloric acid and digestive enzymes are sometimes recommended by practitioners of natural medicine in the hope improved digestion will help prevent reflux.¹ However, these therapies have not been researched for their effectiveness.

According to Jonathan Wright, MD, another cause of heartburn can be too little stomach acid.^[REF] This may seem to be a paradox, but based on the clinical experience of a few doctors such as Dr. Wright, supplementing with betaine HCl (a compound that contains hydrochloric acid) often relieves the symptoms of heartburn and improves digestion, at least in people who have hypochlorhydria (low stomach acid). The amount of betaine HCl used varies with the size of the meal and with the amount of protein ingested. Typical amounts recommended by doctors range from 600 to 2,400 mg per meal. Use of betaine HCl should be monitored by a healthcare practitioner and should be considered only for indigestion sufferers who have been diagnosed with hypochlorhydria.

According to one older report, people with gallstones were likely to have insufficient stomach acid.² Some doctors assess adequacy of stomach acid in people with gallstones and, if appropriate, recommend supplementation with betaine HCl. Nonetheless, no research has yet explored whether such supplementation reduces symptoms of gallstones.

According to preliminary studies from many years ago, lack of hydrochloric acid (HCl) secretion by the stomach was associated with chronic hives, presumably as a result of increasing the likelihood of developing food allergies. In one such study, 31% were diagnosed as having achlorhydria (no gastric acid output), and 53% were shown to be hypochlorhydric (having low gastric acid output).⁴ In a related study, treatment with an HCl supplement and a vitamin B-complex supplement helped to treat people with hives.⁵Betaine HCl is the most common hydrochloric acid-containing supplement; it comes in tablets or capsules measured in grains or milligrams. One or more tablets or capsules, each containing 5–10 grains (325–650 mg) are typically taken with a meal that contains protein. Diagnosis of a deficiency of HCl and supplementation with HCl should be supervised by a doctor.

According to one theory, allergies are triggered by partially undigested protein. Proteolytic enzymes may reduce allergy symptoms by further breaking down undigested protein to sizes that are too small to cause allergic reactions.⁶ Preliminary human evidence supports this theory.⁷Hydrochloric acid secreted by the stomach also helps the digestion of protein, and preliminary research suggests that some people with allergies may not produce adequate amounts of stomach acid.^8,9,10 However, no controlled trials have investigated the use of enzyme supplements to improve digestion as a treatment for food allergies.

Some people with rosacea have been reported to produce inadequate stomach acid.¹¹ In a preliminary trial, supplemental hydrochloric acid, along with vitamin B complex, improved some cases of rosacea in people with low stomach-acid production.¹² Similarly, improvement in rosacea has been reported anecdotally after supplementation with pancreatic digestive enzymes, and a controlled study found that rosacea patients produced less pancreatic lipase than healthy people.¹³ Controlled trials are needed to evaluate the effects of hydrochloric acid and digestive enzyme supplements in rosacea. Hydrochloric acid supplements should not be taken without the supervision of a healthcare practitioner.

People with DH frequently have mild malabsorption (difficulty absorbing certain nutrients) associated with low stomach acid (hypochlorhydria) and inflammation of the stomach lining (atrophic gastritis).¹⁴ Mild malabsorption may result in anemia¹⁵ and nutritional deficiencies of iron, folic acid,^16,17vitamin B12,^18,15 and zinc.^20,16,17 More severe malabsorption may result in loss of bone mass.²³ Additional subtle deficiencies of vitamins and minerals are possible, but have not been investigated. Therefore, some doctors recommend people with DH have their nutritional status checked regularly with laboratory studies. These doctors may also recommend multivitamin-mineral supplements and, to correct the low stomach acid, supplemental betaine HCl (a source of hydrochloric acid).

In one early report, lack of stomach acid (achlorhydria) was associated with vitiligo. Supplementation with dilute hydrochloric acid after meals resulted in gradual repigmentation of the skin (after one year or more).²¹ Hydrochloric acid, or its more modern counterpart betaine HCl, should be taken only under the supervision of a doctor.

It is unknown if taking pancreatic enzymes or betaine HCl (hydrochloric acid) tablets is beneficial for chronic candidiasis. Nonetheless, some doctors recommend improving digestive secretions with these agents. Hydrochloric-acid secretion from the stomach, pancreatic enzymes, and bile all inhibit the overgrowth of Candida and prevent its penetration into the absorptive surfaces of the small intestine.^22,23,24 Decreased secretion of any of these important digestive components can lead to overgrowth of Candida in the gastrointestinal tract. Consult a physician for more information.

It is unknown if taking pancreatic enzymes or betaine HCl (hydrochloric acid) tablets is beneficial for chronic candidiasis. Nonetheless, some doctors recommend improving digestive secretions with these agents. Hydrochloric-acid secretion from the stomach, pancreatic enzymes, and bile all inhibit the overgrowth of Candida and prevent its penetration into the absorptive surfaces of the small intestine.^25,26,27 Decreased secretion of any of these important digestive components can lead to overgrowth of Candida in the gastrointestinal tract. Consult a physician for more information.

Many years ago, two researchers reported that some individuals with RA had inadequate stomach acid.²⁸ Hydrochloric acid, called HCl by chemists, is known to help break down protein in the stomach before the protein can be absorbed in the intestines. Allergies generally occur when inadequately broken down protein is absorbed from the intestines. Therefore, some doctors believe that when stomach acid is low, supplementing with betaine HCl can reduce food-allergy reactions by helping to break down protein before it is absorbed. In theory such supplementation might help some people with RA, but no research has investigated whether betaine HCl actually reduces symptoms of RA.

Supplementation with betaine HCl should be limited to people who have a proven deficit in stomach acid production. Of doctors who prescribe betaine HCl, the amount used varies with the size of the meal and with the amount of protein ingested. Although typical amounts recommended by doctors range from 600 to 2,400 mg of betaine HCl per meal, use of betaine HCl needs to be monitored by a healthcare practitioner and tailored to the needs of the individual.