Whether you're six or 66, drinking milk is supposed to help keep your bones healthy. However, given the bad reputation this beverage has gotten lately, it can be tricky to figure out how much milk you should be drinking every day.
The USDA recommends that you consume three cups of dairy per day to meet your calcium requirements and keep your bones strong. Of this intake, one or two cups can be from milk.
Recommended Dairy Intake
The USDA doesn't specifically define a recommended milk intake. Instead, it offers a broader recommendation for dairy intake. Adult men and women above the age of 50 should aim for three cups of dairy per day.
This intake can be satisfied via a number of dairy products, including milk, yogurt, cheese and calcium-fortified soy milk. It may also include milk-based desserts, such as ice cream, frozen yogurt and milk-based puddings.
However, there is a caveat when it comes to servings. While one cup of milk, yogurt, frozen yogurt, soy milk or milk-based pudding counts as one cup of dairy, the same isn't true for cheese and ice cream. As the USDA points out, 1.5 ounces of hard cheese (such as mozzarella, parmesan, cheddar and Swiss cheese) or two cups of cottage cheese count as one cup of dairy. One and a half cups of ice cream also counts as one cup of dairy.
The USDA's dairy recommendation guidelines are designed to help you fulfill your calcium requirements. Keep in mind that while these foods have been listed as equal because of their calcium content, the amount of other nutrients that they contain, like carbohydrates and fats, varies. Dairy products that don't retain their calcium, such as butter, cream and cream cheese, are not included in this recommendation.
Calcium and Vitamin D Requirements
Calcium and vitamin D are two nutrients that support bone health, according to the National Institutes of Health (NIH). In fact, these nutrients work hand in hand because your body cannot absorb calcium without vitamin D.
The human body uses vitamin D to produce a hormone called calcitriol, which helps absorb calcium from the food you eat. If your body is unable to obtain this mineral from food, it takes the calcium that is stored in your bones, which weakens them.
Insufficient calcium and vitamin D intake can, therefore, lead to osteoporosis, a bone disease caused by bone loss or insufficient bone production. Osteoporosis, a word that means "porous bone," is a condition characterized by weak bones that are more likely to break, especially if you have a fall. Approximately 54 million Americans have either osteoporosis or low bone mass, a risk factor for osteoporosis.
The NIH recommends a daily calcium intake of 1,200 milligrams per day for women above the age of 50, 1,000 milligrams per day for men between the ages of 51 and 70 and 1,200 milligrams per day for men above the age of 70. The recommended vitamin D intake is 600 international units (IU) for people below the age of 70. After the age of 70, it is recommended that you increase your intake to 800 IU per day.
Drinking Milk: Benefits Versus Risks
Milk is a good source of nutrients, including calcium, vitamin D, potassium and protein. One cup of fortified milk provides 314 milligrams of calcium, 397 milligrams of potassium, 100.5 milligrams of vitamin D and 8.53 grams of protein. It also boasts 245 milligrams of phosphorus and 645 milligrams of vitamin A.
So should you be drinking three cups of milk per day to satisfy your calcium requirements and keep your bones healthy? It can be tricky to understand how much milk you need to drink, or whether you need to drink milk at all because for every study that says milk is healthy, there's another one that says it may not be.
The Harvard T.H. Chan School of Public Health (HSPH) takes into account the various health benefits and risks associated with milk consumption and recommends that you limit your milk intake to one or two cups per day.
According to the HSPH, milk can be a convenient source of calcium, which is key to maintaining bone health. This beverage may also help reduce the risk of high blood pressure and colon cancer. However, the HSPH notes that there are no additional health benefits to gain from drinking more milk than that and, in fact, you could open yourself up to health risks, such as greater odds of developing prostate and ovarian cancer.
Drinking milk can also cause gastrointestinal problems like bloating, cramping, gas and diarrhea in people who are lactose intolerant. People with lactose intolerance who are not too fond of dairy products can get their nutrition from non-dairy sources of calcium and vitamin D.
For those who are lactose intolerant and enjoy dairy products, the HSPH recommends drinking milk that has lactase enzymes added to it, taking enzymes or opting for other forms of dairy like yogurt and aged cheeses that have a lower lactose content.
Additional Sources of Nutrition
The HSPH recommends getting the rest of your calcium from other sources. Apart from the other foods in the dairy group, the NIH notes that calcium is also found in non-dairy foods, such as kale, broccoli, spinach, Chinese cabbage, soybeans, oatmeal, baked beans, sardines and salmon. Many types of fruit juices, drinks, tofu and cereals are also fortified with calcium.
Apart from milk and dairy products, the NIH states that there are other sources of vitamin D you may eat. Non-dairy forms of vitamin D include egg yolks, liver and saltwater fish. Like calcium, many foods are fortified with this nutrient as well.
Your body also makes vitamin D naturally when your skin is exposed to the sun. However, factors like the season, time of day, cloud cover and melanin content in your skin can affect how much vitamin D you synthesize. You may require dietary supplements to meet your daily requirement of this nutrient.
- USDA: "All About the Dairy Group"
- Harvard T.H. Chan School of Public Health: "Calcium: What’s Best for Your Bones and Health?"
- National Institutes of Health: "Calcium and Vitamin D: Important at Every Age"
- National Osteoporosis Foundation: "What Is Osteoporosis and What Causes It?"
- USDA: "Milk, Lowfat, Fluid, 1% Milkfat, With Added Nonfat Milk Solids, Vitamin A and Vitamin D"
- USDA: "Dairy: Nutrients and Health Benefits"
- Office of Dietary Supplements: “Vitamin D”