I've heard that some milk fats are required in order to absorb the calcium in milk. Is this correct?

This answer is brought to you by many of the Australian nutrition professionals who regularly contribute to a nutrition email discussion group.

In fact the opposite is more likely to be correct. Fatty acids, particularly saturated fatty acids (which are found in large quantities in milk) form insoluble soaps with calcium. This will lead to LOWER absorption of calcium and increased loss in the faeces. Also, milk sugar (lactose) has been shown to enhance calcium absorption, at least in animals. Although the evidence is less clear for enhanced absorption of calcium in the presence of lactose in adult humans, studies in infants have shown more positive results for the role of lactose.

The most important factor in calcium absorption is the level of vitamin D. Low vitamin D leads to low absorption of calcium. Luckily, in Australia and in other sunny countries in which custom allows exposure of the skin to UV, we produce our own vitamin D, so rickets (a disease caused by insufficient calcium) is extremely rare in this country.

Vitamin D is formed by the action of UV light on a derivative of cholesterol (7-dehydrocholesterol) that is just under the surface of the skin. Although high levels of cholesterol in the blood are associated with increased risk of heart disease, cholesterol is in fact an integral part of the body of every mammal, and contributing to the body's supply of vitamin D is just one of its many vital functions.

For more information Nutrition Australia recommends:

• Adding Life to Your Years
• Eat less fat

Back to Frequently Asked Questions Index

[Date issued: March 1999]

Disclaimer: This material is provided on the basis that it constitutes advice of a general nature only. It is not intended to replace the advice of a physician or a dietitian.