Those who are lactose intolerant may have difficulty consuming enough dairy products to meet their calcium and vitamin D needs. Lactose intolerance occurs when there is a deficiency in the digestive enzyme lactase resulting in an inability to digest lactose, a sugar found in dairy products like milk. Symptoms include abdominal pain, bloating, diarrhea, and nausea, and may occur between 30 minutes and 2 hours after consuming dairy products. The degree of lactose intolerance can vary from individual to individual.
Lactose intolerance often develops in adulthood and may be genetic in origin or the result of injury to the small intestine. Some ethnic groups, including African Americans, Asian Americans, and American Indians, are more affected than others.
Watching Calcium Intake: Milk is the most accessible source of easily digestible calcium with each cup containing 300 mg. Daily needs range from 1000 mg to 1300 mg for those above age 3. Some with mild lactose intolerance can handle 2-3 cups of low fat or nonfat milk spaced throughout the day. Other dairy products, such as yogurt and hard cheese, may contain less lactose than milk. Non-dairy sources of calcium include spinach and other leafy green vegetables, canned fish with bones such as sardines, beans, peas, nuts, and calcium-fortified orange juice and cereal.
Watching Vitamin D Intake: Fortified milk is the best dietary source of vitamin D with approximately 100 IU per cup. Daily needs range from 600 to 800 IU depending on age and gender. Non-dairy sources of vitamin D include fatty fish (salmon, tuna, and swordfish), fortified orange juice, sardines, eggs, and certain mushrooms that have been exposed to UV light.
Supplements: Calcium and vitamin D supplements may help meet nutritional requirements; however, it’s important to check with a doctor before making diet changes or beginning a new supplement. With knowledge and proper planning, those with lactose intolerance can fulfill their calcium and vitamin D needs.
Check out this post I wrote way back when for more on getting the nutrients you need when you are lactose intolerant.
National Digestive Diseases Information Clearinghouse (NDDIC): Lactose Intolerance
Institute of Medicine: Dietary Reference Intakes for Calcium and Vitamin D