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Related to lactose: lactose intolerance


a sugar derived from the milk of mammals, which on hydrolysis yields glucose and galactose; used as a tablet and capsule diluent, a powder bulking agent, and as a component of infant feeding formulas. Many persons are intolerant to lactose as a result of hereditary deficiency of lactase.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.


A reducing disaccharide present in mammalian milk and consisting of a galactosyl residue linked B1,4 to a glucopyranose; obtained from cow's milk and used in modified milk preparation, in food for infants and convalescents, and in pharmaceutical preparations; in large doses, acts as an osmotic diuretic and as a laxative. Human milk contains 6.7% lactose.
Farlex Partner Medical Dictionary © Farlex 2012


A white crystalline disaccharide, C12H22O11, found in milk, that may be hydrolyzed to yield glucose and galactose. Refined lactose obtained from whey is used in infant foods, bakery products, confections, and pharmaceuticals as a diluent and excipient. Also called milk sugar.
The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.


A reducing disaccharide that is hydrolysed by beta-galactosidase into d-galactose and d-glucose; it is synthesised by mammalian mammaries, and causes intolerance to milk products that occurs in some adults.
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.


A disaccharide present in cow's milk and used in food for infants and convalescents and in pharmaceutical preparations; large doses act as an osmotic diuretic and as a laxative.
Synonym(s): milk sugar.
Medical Dictionary for the Health Professions and Nursing © Farlex 2012


The main sugar in milk. It is broken down by the digestive enzyme lactase (beta-galactosidase) to galactose and glucose.
Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005
Lactoseclick for a larger image
Fig. 203 Lactose . The condensation reaction between galactose and glucose.



milk sugar

a DISACCHARIDE carbohydrate found in the milk of mammals. Lactose is produced by a CONDENSATION REACTION between galactose and glucose. See Fig. 203 .

The sugar can be broken into its component monosaccharides by LACTASE. Souring of milk is due to the conversion of lactose to LACTIC ACID by microorganisms present in the milk.

Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005


A sugar found in milk and milk products. Some people are lactose intolerant, meaning they have trouble digesting lactose. Lactose intolerance can produce symptoms resembling those of IBS.
Gale Encyclopedia of Medicine. Copyright 2008 The Gale Group, Inc. All rights reserved.


A disaccharide present in cow's milk and used in food for infants and convalescents and in pharmaceutical preparations.
Synonym(s): milk sugar.
Medical Dictionary for the Dental Professions © Farlex 2012

Patient discussion about lactose

Q. can you be lactose intolerant just in the morning? if i drink milk or eat a dairy product in the morning i get nausous, vomit and have diarehha. but i eat dairy products in the evening and im fine. is it possible to be lactose intolerant just in the morning?

A. Not that I'm aware of.. You are either lactose intolerant or you're not. However, it depends on how much dairy products you eat, and perhaps you consume more dairy products in the morning, on an empty stomach, where it all absorbs, where as in the evening you might eat less and combine it with other food. I would suggest you dicrease the total amount of dairy you eat, in order to get rid of these symptms.

Q. lactose intolerant If you are lactose intolerant and you consume a dairy related product can it cause a fever?

A. No
Lactose Intolerance means you lack the enzyme to digest milk.
You get diarrhea NOT fever

Q. I am lactose intolerant. Can I have any other dairy food?

A. If you are lactose intolerant then you must avoid all lactose containing foods like milk, yoghurt & cheese. You can consume these dairy products If your intolerance is less or else you can have cultured yoghurt and lactobacillus milk as a better dairy option.

More discussions about lactose
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References in periodicals archive ?
*Lactase can also reduce the possibility of crystallization of lactose in ice cream, concentrated milk, and light condensed milk while increasing sweetness.
Certain people are more prone to having lactose intolerance more than others.
Although lactose intolerance can be genetic, some individuals acquire lactose intolerance as they age since their body no longer creates as much lactase.
Congenital lactase deficiency is a rare condition.13 Currently the treatment options for lactose intolerance include lactose-reduced diet, limiting the consumption of milk or using low-lactose milk, and using supplemental lactase or probiotics.13 Low intake of milk would cause low intake of calcium and vitamin D and has negative effect on bones and teeth development in infants.14 Therefore lactase supplements or probiotics are better options to treat lactose intolerance.
A reduction of at least 50% of enzyme activity is required to trigger the symptoms resulting from the primary deficiency of lactase, which explains part of the variation in tolerance to small doses of lactose by individuals with lactose intolerance.
The researchers studied crystallization in aqueous solutions by adding propylene glycol at 0% to 30% w/w of lactose in 40% w/w lactose solutions, which were incubated for 24 hours at 4 C.
This process replaces pasteurization, which lowers the lactose level even more.
Many people with LI are able to tolerate yogurt, especially Greek yogurt, since it contains about half the lactose of regular yogurt.
"Just like me, a huge percentage of the Indian population is lactose intolerant but most of them do not even know it.
[18] employed FTIR technique for differentiate the crystalline lactose from the amorphous.
In the meat industry, the sugars added to meat products include sucrose and lactose (disaccharides) [4, 5], honey and rice syrup [1], and glycerol and sorbitol [16].