Milk is an excellent source of calcium. Green, leafy vegetables and pulses also contain calcium.

To get the same amount of calcium as you would from one glass of milk, you need to eat more than 9 servings of leafy spinach, more than 8 portions of red kidney beans or more than 4 servings of broccoli.

Cow's milk: Milk is divided into different types depending on its fat content:

- Whole- or full-fat milk contains around 3.5-4 per cent fat

- Semi-skimmed or low-fat milk contains around 1.5-1.8 per cent fat

- Skimmed milk contains less than 0.5 per cent fat

- Contrary to popular belief, semi-skimmed and skimmed milk contain more calcium than whole milk.

Organic milk: This is produced without the use of antibiotics, hormones or pesticides. Cows are raised on certified organic feed for at least one year before making certified organic milk.

The cows' feed is grown on land that has been pesticide-free for at least three years. The cows are not treated with synthetic growth hormones or antibiotics. Organic milk never comes into contact with any non-organic milk.

Evaporated milk: This is made by removing around 60 per cent of the water from whole- or full-fat cow's milk. Vitamins A and D are sometimes added, then the milk is canned and sterilised by heat.

Condensed milk: This is made by removing around 60 per cent of the water from full-fat cow's milk and adding a large amount of sugar. Sugar acts as a preservative which means that condensed milk doesn't have to be heated or sterilised.

How much calcium do I need?

Teens need around 1,300mg of calcium a day to grow and build bones. This can be easily met by including 2 glasses of reduced-fat milk, 1 pot of yoghurt and a serving of salmon in the daily diet.

What if I can't drink milk?

Lactose is the sugar found in milk and dairy products.

A person with lactose intolerance has a problem digesting or breaking down this sugar. They may suffer from bloating, stomach pains, diarrhoea and gas after drinking large quantities of milk.

Usually a person with lactose intolerance can cope with small amounts of milk and dairy products, especially if these are eaten with other foods at the same time, for example, milk in cereal or a cheese sandwich.

Fun facts

The average cow produces 90 glasses of milk each day; that's around 200,000 glasses of milk throughout her life.

Cows can only produce milk after they have given birth.

A cow needs to drink over 430 litres of water a week to produce milk.

Milk maths

A 240ml glass of whole milk contributes a big percentage of your recommended daily requirements of vitamins and minerals:

25% calcium

16% protein

11% potassium

10% vitamin A

13% vitamin B12

24% vitamin B2 (riboflavin)

10% vitamin B3 (niacin)

20% phosphorous

Nutrition know-how

1. What are the main nutrients found in milk?

a) Carbohydrates, vitamin D and vitamin A

b) Calcium, phosphorous, magnesium, B vitamins, vitamin A and protein

c) Fibre, B vitamins, calcium and selenium

2. How many glasses of milk do you need to drink to meet your daily requirement for calcium?

a) More than 5 glasses

b) Just over 3 glasses

c) 1-2 glasses

3. What is the difference between condensed and evaporated milk?

a) Condensed milk has sugar added. Evaporated milk sometimes has vitamins A and D added and is canned and sterilised by heat.

b) Condensed milk has vitamins added and evaporated milk has sugar added.

c) There is no difference.

4. Which of the following mineral is important for building strong bones and teeth?

a) Iodine

b) Sulphur

c) Calcium

5. Which sugar is found in milk?

a) Sucrose

b) Glucose

c) Lactose

Answers

1. b, 2. b, 3. a, 4. c, 5. c