As much as 75 percent of the world's population has lactose intolerance, according to the Toronto Vegetarian Association. Lactose intolerance normally occurs as an inherited condition caused by lack of an intestinal enzyme, lactase, produced in the villi of the small intestine. Lactase breaks down lactose, the sugar found in milk, into glucose and galactose, so the intestines can absorb it. Iron deficiency and lactose intolerance sometimes occur concurrently in individuals with certain health conditions, but one does not cause the other.
Lactose Intolerance Characteristics
Lactose intolerance normally develops in teens or young adults, but it can develop at any age. Lactose intolerance rarely occurs before age 2. Lactose intolerance causes gas, diarrhea, bloating and abdominal discomfort within 30 minutes to two hours when you consume lactose. Different people have different tolerance for lactose; some people can consume moderate amounts without difficulty while others have a higher sensitivity. Lactose intolerance occurs less frequently in Caucasians and more often in blacks, Asians and Hispanics.
Iron Deficiency Symptoms
Blood loss can cause iron deficiency, since red blood cells carry iron. Iron deficiency causes fatigue, pallor, weakness and shortness of breath on exertion. Rapid heartbeat, heart murmurs, dizziness, headache, extreme sensitivity to cold and chest pain can also occur. You may develop cracks in the corners of your mouth or spoon-shaped nails.
Milk Allergy vs. Lactose Intolerance
Milk allergy, not lactose intolerance, can cause iron deficiency. Milk allergy, a completely different condition from lactose intolerance, occurs when you have an allergy to the proteins in milk. Milk allergy can cause irritation of the stomach and intestines that leads to microscopic bleeding. Chronic blood loss can lead to iron loss and iron deficiency. The damaged intestine may also not absorb iron well, also contributing to iron deficiency. Damage to the intestine from milk allergy can also lead to lactose intolerance, because damage to the villi in the small intestines decreases the amount of lactase produced.
Common Causes
Lactose intolerance and iron deficiency can occur at the same time in other diseases that cause intestinal inflammation, such as celiac disease and Crohn's disease. Drinking large amounts of milk can also lead to iron deficiency, since substances in the milk can interfere with iron absorption, the Toronto Vegetarian Association states.
References
- Science in Africa; Milk Allergy and Lactose Intolerance; Dr. Harris Steinman; May 2002
- Better Health Channel; Lactose Intolerance; July 2009
- Toronto Vegetarian Association; Cow's Milk: A Natural Choice?; March 2005
- Parkhurst Exchange; Lactose Intolerance; Robert J. Fingerote, M.D.; October 2008
- Information Center for Sickle Cell and Thalassemic Disorders: Iron Deficiency
- National Heart, Lung and Blood Insitute: Iron Deficiency Anemia
