Cow's Milk: Nutrients, What Research Shows and Safety

Cow's milk is the white liquid from dairy cows (Bos taurus), sold as whole, reduced-fat, low-fat and fat-free milk, and also as lactose-free milk. In the United States, milk sold as a drink must be pasteurized, which is a heat step that kills germs. [1] The NHS calls milk and dairy good sources of protein and calcium. [2] This page treats milk as a drink. It keeps cheese, yogurt and other ferments, plant milks and supplements apart, and it separates what studies of people found from hype.

Read this first

• Allergy: milk is one of the nine major food allergens named by the U.S. FDA. [3] Milk allergy is an immune reaction to milk protein. Lactose intolerance is a different problem: the gut cannot digest milk sugar. [4] [5] For trouble breathing, swelling of the lips, tongue or throat, or a very fast reaction, call 911 (or your local emergency number). The NHS gives the same kind of warning signs and says to call 999 in the UK. [5]
• Raw (unpasteurized) milk can carry germs such as Listeria, Salmonella and E. coli. CDC lists children under 5, adults over 65, pregnant women and people with weak immune systems as higher-risk. [6] Pasteurized milk gives the same nutrition without those risks, CDC says. [6]
• Babies: CDC says to introduce cow's milk as a drink at 12 months, not before. [7]
• Evidence in one line: large studies that follow people over time found no clear link between milk and deaths or heart disease, but such studies cannot prove cause and effect. [8] Official advice on fat level differs: the 2025-2030 U.S. Dietary Guidelines say to include full-fat dairy with no added sugars, while the NHS says adults and older children can switch to 1% or skimmed milk. [9] [2]

What is in it (USDA values)

The values below are for whole milk (3.25% milkfat) with added vitamin D (USDA FoodData Central item 171265, SR Legacy). [10] The serving column is the USDA household portion of 1 cup, 244 g. A second USDA record for whole milk without added vitamins A and D lists the same energy, protein and calcium. [11]

% Daily Value uses the FDA 2016 Daily Values; values vary by milk fat level, brand and season. The serving figures are the 100 g values multiplied by 2.44. Total sugars in plain milk are mostly lactose, the natural milk sugar, and the U.S. Dietary Guidelines say naturally occurring sugars in plain milk are not counted as added sugars. [9] Reduced-fat and fat-free milks have less fat and fewer calories; we did not put their USDA records in this table. In the U.S. rule for milk, vitamin D is an optional addition (400 International Units per quart if added). [1]

Plant compounds: milk is mainly water, lactose, fat and protein. Proper evidence not found in the sources we read for a named plant compound or "bioactive" in milk that has been shown to matter for health in people, so we make no claim.

What research says

Observational studies show associations. People who drink more or less milk also differ in other ways, so these studies cannot prove that milk caused a result. The abstracts we read did not report who paid for the studies.

Eaten as food vs other forms. The studies above mostly measured milk or "dairy" as a food or drink. Cheese, yogurt (fermented dairy), butter and milk-protein supplements are different products, and our sources group them differently. [8] This page does not cover supplements.

How much is a normal serving

The USDA household portion is 1 cup (244 g), which has 149 kcal as whole milk. [10] The 2025-2030 U.S. Dietary Guidelines give a dairy goal of 3 servings a day in a 2,000-calorie pattern, to be adjusted to your calorie needs. [9] CDC says children aged 12 to 23 months need about 2 servings of dairy a day and that milk should add to food, not replace it. [7] The NHS says about 300 ml of milk provides roughly the 350 mg of calcium children aged 1 to 3 need. [2] These are official figures, given as information, not a prescription for you.

For saturated fat, the Guidelines say it should not exceed 10% of daily calories. [9] On a 2,000-calorie day that is about 22 g (our arithmetic: 200 kcal divided by 9 kcal per gram). One cup of whole milk has 4.55 g.

Safety, allergy and medicines

• Milk allergy: milk allergy is one of the most common food allergies in early childhood, and the World Allergy Organization nutrition guideline does not recommend other animals' milks as substitutes because of high cross-reactivity. [17] Lactose-free milk is regular milk with the enzyme lactase added, so we cannot say it is safe in milk allergy. [2] Ask an allergist. [17]
• Lactose intolerance: symptoms include belly pain, bloating, gas and diarrhea, starting minutes to hours after lactose. [4] MedlinePlus says eating less lactose or using lactase pills or drops usually helps. [18] The NHS says not to cut foods out of a child's diet without advice from a GP or dietitian. [4] See also lactose intolerance.
• Raw milk: CDC says raw milk can cause diarrhea, cramps and vomiting and, rarely, serious illness such as kidney failure or Guillain-Barre syndrome. Good farm practice cannot guarantee it is germ-free. [6] See raw milk claims checked.
• Pregnancy: CDC lists pregnant women as higher-risk for Listeria and says to choose pasteurized milk and avoid raw milk. [19] The NHS says pregnant women should only drink pasteurized or UHT milk. [2] The Dietary Guidelines list calcium-rich dairy among foods for pregnancy. [9]
• Babies and children: CDC says not to give cow's milk as a drink before 12 months, with risks that include possible intestinal bleeding and too much protein and minerals for a baby's kidneys. It advises pasteurized, unflavored, unsweetened milk and never raw milk. [7] The Dietary Guidelines say full-fat dairy helps children meet energy needs. [9]
• Medicines: we did not find a source we could read that names a direct interaction between milk as a drink and a specific medicine. MedlinePlus says calcium carbonate and iron supplements should be taken at least 4 hours apart from levothyroxine; its page does not mention milk, so ask your pharmacist about timing. [20] See foods and medicine interactions.
• Kidney disease: NIDDK says dairy is a natural source of phosphorus and that people with kidney disease may be told to limit meat and dairy. Work with a dietitian. [21] See foods in kidney disease.
• Diabetes and blood sugar: a cup of whole milk has 4.8 g carbohydrate per 100 g, about 11.7 g per cup, mostly lactose. [10] We did not read a trial of milk and blood sugar control. Ask your care team how to count it.

Choosing, storing and food safety

• Choose pasteurized milk. Milk sold as a drink in the U.S. must be pasteurized or ultra-pasteurized, and the label says "ultra-pasteurized" if that process was used. [1]
• Keep milk refrigerated and respect the use-by date. The NHS gives this advice for unpasteurized milk; we did not read a separate rule for pasteurized milk. [2]
• For toddlers, choose unflavored and unsweetened milk. [7] Flavored milk was not covered in the sources we read, so check the label for added sugar.

Related pages

• Plant milks: oat, almond, soy and others
• Soy milk
• Food allergy basics and emergency signs
• Foods in pregnancy: what official bodies advise
• Foods for babies and toddlers: choking, honey and allergens
• Raw sprouts, raw milk and undercooked foods: risks