Milk and calcium do the body good
RECENT disputes about the quality standards of domestic milk have made many people think twice when drinking milk. Yet milk remains the best source of calcium, according to nutrition experts. Yogurt and cheese are good substitutes for those who can't drink milk.
Calcium is one of the major inorganic elements in the body. A lack of calcium has been linked to problems such as achy joints and bones, fatigue, poor appetite, sleeplessness and anxiousness. Osteoporosis and rickets have also been linked to a lack of calcium.
The average adult needs about 800mg of calcium a day, according to Yang Kefeng, a nutritionist from Shanghai Jiao Tong University's Nutrition Department with the School of Medicine. Pregnant women need about 1,000mg per day. Toddlers 1 to 3 years old need 500mg, children 4 to 8 years need 800mg and those from 9 to 18 years require 1,300mg daily.
Generally, the average adult is advised to drink about 250ml of milk every day. Ordinary milk is the best choice for most healthy people, while people with problems like high blood pressure, high blood fat, diabetes or metabolism problems are suggested to drink evaporated milk.
"High-calcium milk in the market is usually made by adding more calcium carbonate. Though it helps increase the calcium content in milk, it does not necessarily increase the quantity of calcium that you can absorb," Yang says.
As for the recent heated debate on pasturized milk and ultra-high-temperature processed milk, Yang suggests that both processing methods retain both the protein and calcium, while some vitamins are lost in the ultra-high-temperature processing.
Generally, 100 milliliters of milk contains about 110mg of calcium and it has a high absorption rate of more than 32 percent. About one-third of the calcium in milk exists in a free state that can be directly absorbed by the body. The rest is in casein that is released and largely absorbed during digestion.
Though some vegetables are rich in calcium - like kale, spinach, cabbage, okra and various beans - the oxalic acid in these foods usually lowers the absorption of many micro elements including calcium.
For example, calcium absorption from spinach is only 1/6 of that from milk. Though cabbage has a better absorption rate, it contains only 30mg of calcium per 100g, which means you would have to eat about 1kg to get the same quantity of calcium from 300ml of milk.
Of course, milk is not suitable for everyone. For those who are lactose intolerant or have digestive problems, baked beans, leafy green vegetables (like broccoli, spinach and more), oatmeal and calcium-fortified foods are good ways to ensure you get enough calcium.
Yang also says it is important to get enough vitamin D, which helps the body absorb calcium. The nutritionist also recommends avoiding drinking milk on an empty stomach or at the same time as fruit and fruit juices as this will decrease calcium absorption.