by Jason P. Smith
A recent study conducted by Swiss researchers at the University Hospital in Uppsala, Sweden found that an increased level of vitamin A, a vitamin associated with bone development, may lead to an increased risk of broken bones in older men.
This study, according to the New England Journal of Medicine, supports the results of two previous studies conducted with women, which makes the risks of excess vitamin A problematic for both men and women. Vitamin A can be found in various foods people eat on a daily basis, such as dairy products, eggs, fish liver oil and beef liver, which is among the most highly concentrated sources of vitamin A. The study’s report states that many people, due to food fortification and supplements in Western countries, are getting too much of a good thing.
The study looked at 2,322 men between the ages of 49 to 51. The men were followed for 30 years and, as it turned out, the men with the highest blood levels of vitamin A at the beginning of the study were 1.6 times as likely to break a bone as men with an average amount of vitamin A in their blood, according to the study.
When it came to breaking a hip, one of the most common and most serious bones for older adults to break, those with increased levels of vitamin A had a 2.5-fold greater risk than men with lower levels of vitamin A. Overall, 266 men broke a bone during the study. According to the study, there was no link between blood levels of beta-carotene, a compound that is converted to vitamin A in the body, and fracture risk.
Vitamin A is an essential vitamin for many things, including night vision development, bone development, reproduction, a strong immune system and healthy skin, but too much has been considered dangerous for a number of years. Vitamin A is measured primarily in International Units. The recommended vitamin A intake for children ages 1 to 3 is 2,000 IU; 2,500 IU for children ages 4 to 6; and 3,500 IU for children ages 7 to 10. The recommended IU intake for those ages 11 through adulthood is 5,000 IU for men and 4,000 IU for women, which includes women who are pregnant and nursing.
It is difficult, without a guide, to figure out exactly how much vitamin A is in the foods people eat, but resources are available to help people track how much vitamin A is in the various foods they may eat. According to the "Encyclopedia of Nutritional Supplements" by Michael T. Murray, a naturopathic physician, 3 ½ ounces of beef liver contains 43,900 IUs of vitamin A, 3 ½ ounces of sweet potato contains 8,800 IUs and the same amount of cantaloupe has 3,400 IUs.
There are many different sources for vitamin A and a good deal of it is needed for proper development in many areas, but too much can have harmful side effects. The study also suggests that with the life expectancy increasing in Western nations, there also may be a connection to the increase of osteoporosis.