Treatment algorithm

Please note that formulations/routes and doses may differ between drug names and brands, drug formularies, or locations. Treatment recommendations are specific to patient groups: see disclaimer

ACUTE

demonstrating symptoms of lactose intolerance

1st line – dietary modification

Back
ACUTE
|
demonstrating symptoms of lactose intolerance
|
primary (hereditary: due to lactase non-persistence)
1st line – 

dietary modification

Most common cause of lactose malabsorption and lactose intolerance due to lactase non-persistence. Develops in childhood at various ages although it is uncommon before 2-3 years of age.

Patients should experiment carefully with a variety of foods to discover their lactose threshold. Most patients can tolerate a glass of milk (240 mL = 11 g lactose) a day, whereas others develop symptoms with just 2-3 g lactose from a chocolate bar.[5][27]​​

Encourage patients to acquaint themselves with the lactose content of common foods. University of Virginia Digestive Health Center: lactose content of common dairy foods Opens in new window​ The following dairy products may be tolerated due to lower lactose levels: hard cheeses, live-culture yoghurts, live-culture curds, live-culture cheeses, and milk-cereal mixtures.

Lactose-free and lactose-reduced dairy products (e.g., cow’s milk or cheese pre-treated with lactase) and non-dairy alternatives (e.g., soya milk, coconut milk, oat milk, rice milk) are commercially available.[2][65]

Patients with severe symptoms should actively look for and avoid lactose-containing dairy and non-dairy products.[1][67][68] Many processed and ready-to-eat foods, and some weight-reducing diet foods, are high in lactose but lack appropriate labelling. Some patients with coexistent irritable bowel syndrome that is responsive to a diet that is low in fermentable oligo-, di-, monosaccharides and polyols (FODMAPs) may feel gastrointestinal symptomatic improvement with reduction of both lactose and FODMAPs.[60][69]

Plus – dietitian consultation

Back
ACUTE
|
demonstrating symptoms of lactose intolerance
|
primary (hereditary: due to lactase non-persistence)
Plus – 

dietitian consultation

Treatment recommended for ALL patients in selected patient group

Dietitian consultation should be sought at diagnosis, then yearly, and also if persistent symptoms suggest a source of hidden lactose. Dietitians will not only stress long-term use of low-lactose (or lactose-free) dairy products, but will also give advice on diets rich in calcium and vitamin D.[58][59] National Academies: dietary reference intakes for calcium and vitamin D Opens in new window​ Advice regarding substitution of alternative nutrient sources to maintain good energy and protein intake is also very important.

Consider – probiotics

Back
ACUTE
|
demonstrating symptoms of lactose intolerance
|
primary (hereditary: due to lactase non-persistence)
Consider – 

probiotics

Additional treatment recommended for SOME patients in selected patient group

Lactase-containing probiotics have the potential to help lactose digestion.[72] However, studies report varying degrees of benefit, and effects depend on the dose and formulation of the probiotic.[62][73][74]​​

Consider – oral lactase supplementation

Back
ACUTE
|
demonstrating symptoms of lactose intolerance
|
primary (hereditary: due to lactase non-persistence)
Consider – 

oral lactase supplementation

Additional treatment recommended for SOME patients in selected patient group

Lactase preparations are readily available and will often permit a lactose-intolerant person to be able to take some or all milk products freely. Fungal-derived lactase replacement is particularly effective and well tolerated.[70][71]

Consider – calcium

Back
ACUTE
|
demonstrating symptoms of lactose intolerance
|
primary (hereditary: due to lactase non-persistence)
Consider – 

calcium

Additional treatment recommended for SOME patients in selected patient group

Although there is a lack of evidence supporting calcium and vitamin D replacement for patients with lactose intolerance, most clinicians endorse this approach in practice.[60]​ Lactose malabsorption does not predispose to calcium malabsorption, but avoidance of dairy products may be problematic for optimal bone mineralisation.[5][75]​​

Reduction in calcium intake should be compensated with other calcium-rich foods or calcium supplementation when there is elimination or significant reduction of dairy products, severe symptoms associated with calcium and vitamin D deficiency or osteopenia, or a requirement for a DEXA scan.[2][76]​​

Primary options

calcium gluconate: 1000-1500 mg orally/day

More

Consider – vitamin D supplementation and monitoring of vitamin D status

Back
ACUTE
|
demonstrating symptoms of lactose intolerance
|
primary (hereditary: due to lactase non-persistence)
Consider – 

vitamin D supplementation and monitoring of vitamin D status

Additional treatment recommended for SOME patients in selected patient group

Although there is a lack of evidence supporting calcium and vitamin D replacement for patients with lactose intolerance, most clinicians endorse this approach in practice.[60]

When there is elimination or significant reduction of dairy products, vitamin D supplementation should be considered, with monitoring of vitamin D status every 6-12 months, in line with local protocols.[58]​ Patients with severe symptoms associated with calcium and vitamin D deficiency, and patients with osteopenia on DEXA scans, require adjunctive calcium and vitamin D supplementation. See also, Vitamin D deficiency (treatment algorithm).

Primary options

ergocalciferol: 600-2000 international units orally once daily depending on age and degree of deficiency

1st line – treatment of underlying cause

Back
ACUTE
|
demonstrating symptoms of lactose intolerance
|
secondary (acquired: secondary to injury to the small intestinal mucosa)
1st line – 

treatment of underlying cause

Treatment of secondary disease and lactose malabsorption attributable to an underlying condition involves treatment of underlying causes. For example, intravenous fluids and total parenteral nutrition for small bowel injury; oral hydration fluids for acute gastroenteritis; doxycycline for small bowel bacterial overgrowth; gluten-free diet for coeliac sprue; and octreotide, intravenous fluid, and antiemetics for cancer chemotherapy.

Plus – dietitian consultation

Back
ACUTE
|
demonstrating symptoms of lactose intolerance
|
secondary (acquired: secondary to injury to the small intestinal mucosa)
Plus – 

dietitian consultation

Treatment recommended for ALL patients in selected patient group

Dietitian consultation should be sought at diagnosis then yearly, and also if persistent symptoms suggest a source of hidden lactose. Dietitians will not only stress long-term use of low-lactose (or lactose-free) dairy products, but will also give advice on diets rich in calcium and vitamin D.[58][59] National Academies: dietary reference intakes for calcium and vitamin D Opens in new window​ Advice regarding substitution of alternative nutrient sources to maintain good energy and protein intake is also very important.

Consider – temporary dietary modification

Back
ACUTE
|
demonstrating symptoms of lactose intolerance
|
secondary (acquired: secondary to injury to the small intestinal mucosa)
Consider – 

temporary dietary modification

Additional treatment recommended for SOME patients in selected patient group

Dairy products may need to be temporarily restricted in some patients with significant symptoms of lactose intolerance for symptomatic improvement.

Lactose-containing products can often be consumed normally after resolution of the primary problem.[2][14][57]

Consider – probiotics

Back
ACUTE
|
demonstrating symptoms of lactose intolerance
|
secondary (acquired: secondary to injury to the small intestinal mucosa)
Consider – 

probiotics

Additional treatment recommended for SOME patients in selected patient group

Lactase-containing probiotics have the potential to help lactose digestion.[72] However, studies report varying degrees of benefit, and effects depend on the dose and formulation of the probiotic.[62][73][74]​​

Consider – oral lactase supplementation

Back
ACUTE
|
demonstrating symptoms of lactose intolerance
|
secondary (acquired: secondary to injury to the small intestinal mucosa)
Consider – 

oral lactase supplementation

Additional treatment recommended for SOME patients in selected patient group

Lactase preparations are readily available and will often permit a lactose intolerant individual to take some or all milk products freely. Fungal-derived lactase replacement is particularly effective and well tolerated.[70][71]

Consider – calcium

Back
ACUTE
|
demonstrating symptoms of lactose intolerance
|
secondary (acquired: secondary to injury to the small intestinal mucosa)
Consider – 

calcium

Additional treatment recommended for SOME patients in selected patient group

Although there is a lack of evidence supporting calcium and vitamin D replacement for patients with lactose intolerance, most clinicians endorse this approach in practice.[60]​ Lactose malabsorption does not predispose to calcium malabsorption, but avoiding dairy products may be problematic for optimal bone mineralisation.[5][75]​​​ Reduction in calcium intake should be compensated with other calcium-rich foods or calcium supplementation when there is elimination or significant reduction of dairy products, severe symptoms associated with calcium and vitamin D deficiency or osteopenia, or a requirement for a DEXA scan.[2][76]​​

Primary options

calcium gluconate: 1000-1500 mg orally/day

More

Consider – vitamin D supplementation and monitoring of vitamin D status

Back
ACUTE
|
demonstrating symptoms of lactose intolerance
|
secondary (acquired: secondary to injury to the small intestinal mucosa)
Consider – 

vitamin D supplementation and monitoring of vitamin D status

Additional treatment recommended for SOME patients in selected patient group

Although there is a lack of evidence supporting calcium and vitamin D replacement for patients with lactose intolerance, most clinicians endorse this approach in practice.[60]

When there is elimination or significant reduction of dairy products, vitamin D supplementation should be considered, with monitoring of vitamin D status every 6-12 months, in line with local protocols.[58]​ Patients with severe symptoms associated with calcium and vitamin D deficiency, and patients with osteopenia on DEXA scans, require adjunctive calcium and vitamin D supplementation. Children with lactose malabsorption due to secondary causes of hypolactasia, such as coeliac disease, may also warrant screening for vitamin D deficiency due to risk of reduced bone mass and fractures in these conditions.[76]​ See also, Vitamin D deficiency (treatment algorithm).

Primary options

ergocalciferol: 600-2000 international units orally once daily depending on age and degree of deficiency

1st line – oral lactase supplementation

Back
ACUTE
|
demonstrating symptoms of lactose intolerance
|
developmental (relative deficiency: in preterm infants <34 weeks' gestation rapidly improving as intestinal mucosa matures)
1st line – 

oral lactase supplementation

It is recommended that all premature infants are breastfed and/or given lactose-containing formulas. Those who develop symptoms of lactose intolerance may be fed with lactase supplements for a period of a few weeks to 2 months.[2]

Lactase supplements may be taken with formula containing lactose or with human milk, as there is no evidence that either human milk or formulas containing lactose have short- or long-term deleterious effects on preterm infants.[78]

Consider – avoidance of lactose-containing formula and human milk

Back
ACUTE
|
demonstrating symptoms of lactose intolerance
|
developmental (relative deficiency: in preterm infants <34 weeks' gestation rapidly improving as intestinal mucosa matures)
Consider – 

avoidance of lactose-containing formula and human milk

Additional treatment recommended for SOME patients in selected patient group

Avoiding lactose-containing formula and human milk is only recommended in patients with severe symptoms of lactose intolerance; if necessary, it is only recommended for a very short period.[79]

1st line – diarrhoea management

Back
ACUTE
|
demonstrating symptoms of lactose intolerance
|
congenital (lifelong disorder requiring complete avoidance of lactose)
1st line – 

diarrhoea management

Without early recognition and prompt treatment, congenital lactase deficiency is potentially life threatening. Initial management of diarrhoea includes intravenous rehydration and replacement of electrolytes.

Plus – complete avoidance of lactose from birth

Back
ACUTE
|
demonstrating symptoms of lactose intolerance
|
congenital (lifelong disorder requiring complete avoidance of lactose)
Plus – 

complete avoidance of lactose from birth

Treatment recommended for ALL patients in selected patient group

Without early recognition and prompt treatment, congenital lactase deficiency is potentially life threatening.

The only treatment apart from management of diarrhoea is complete avoidance of lactose from birth. Treatment is lifelong and consists of simple removal of lactose from the diet and substitution with a commercial lactose-free formula.

Plus – dietitian consultation

Back
ACUTE
|
demonstrating symptoms of lactose intolerance
|
congenital (lifelong disorder requiring complete avoidance of lactose)
Plus – 

dietitian consultation

Treatment recommended for ALL patients in selected patient group

Dietitian consultation should be sought at diagnosis, then yearly; and also if persistent symptoms suggest a source of hidden lactose. Dietitians will not only stress long-term use of low-lactose (or lactose-free) dairy products, but will also give advice on diets rich in calcium and vitamin D.[58][59] National Academies: dietary reference intakes for calcium and vitamin D Opens in new window​ Advice regarding substitution of alternative nutrient sources to maintain good energy and protein intake is also very important.

Consider – calcium

Back
ACUTE
|
demonstrating symptoms of lactose intolerance
|
congenital (lifelong disorder requiring complete avoidance of lactose)
Consider – 

calcium

Additional treatment recommended for SOME patients in selected patient group

Although there is a lack of evidence supporting calcium and vitamin D replacement for patients with lactose intolerance, most clinicians endorse this approach in practice.[60]​ Lactose malabsorption does not predispose to calcium malabsorption, but avoidance of dairy products may be problematic for optimal bone mineralisation.[5][75]​​​ Reduction in calcium intake should be compensated with other calcium-rich foods or calcium supplementation when there is elimination or significant reduction of dairy products, severe symptoms associated with calcium and vitamin D deficiency or osteopenia, or a requirement for a DEXA scan.[2][76]​​

Primary options

calcium gluconate: 210-1300 mg/day orally

More

Consider – vitamin D supplementation and monitoring of vitamin D status

Back
ACUTE
|
demonstrating symptoms of lactose intolerance
|
congenital (lifelong disorder requiring complete avoidance of lactose)
Consider – 

vitamin D supplementation and monitoring of vitamin D status

Additional treatment recommended for SOME patients in selected patient group

Although there is a lack of evidence supporting calcium and vitamin D replacement for patients with lactose intolerance, most clinicians endorse this approach in practice.[60]

When there is elimination or significant reduction of dairy products, vitamin D supplementation should be considered, with monitoring of vitamin D status every 6-12 months, in line with local protocols.[58]​ Patients with severe symptoms associated with calcium and vitamin D deficiency, and patients with osteopenia on DEXA scans, require adjunctive calcium and vitamin D supplementation. See also, Vitamin D deficiency (treatment algorithm).

Primary options

ergocalciferol: 400-2000 international units orally once daily depending on age and degree of deficiency

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Please note that formulations/routes and doses may differ between drug names and brands, drug formularies, or locations. Treatment recommendations are specific to patient groups. See disclaimer

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