The more obese a person is, the poorer his or her vitamin D status, a recent study by a team of Norwegian researchers suggests. The study found an inverse relationship between excess pounds and an insufficient amount of vitamin D, which is critical to cell health, calcium absorption and proper immune function. Vitamin D deficiency can raise the risk for bone deterioration and certain types of cancer.

Study Details

To investigate the impact of obesity on vitamin D absorption, the team spent six years tracking 1,464 women and 315 men, with an average age of 49. Based on the participants' body mass index (BMI), a measure of body fat calculated from a person's weight and height, the average participant was deemed to be obese. About 11% were categorized as "morbidly obese."

From the outset, overall vitamin D levels were found to be below the healthy range, the authors noted. By the end of the study, overall levels of vitamin D were found to have dropped off "significantly" while BMI readings rose by 5%.

The research team concluded that having a higher-than-normal weight, body fat and BMI was linked to a poorer vitamin D profile.

For example, people with the lowest BMI readings had 14% higher vitamin D levels than those with the highest BMI readings.

The findings were published in the Journal of Nutrition.

Vitamin D Conversion Process Thwarted By Obesity

The researchers also suggest that overweight and obese people may have problems processing the vitamin properly. After the so-called "sunshine vitamin" is initially absorbed (through either sun exposure or the consumption of such foods as oily fish and fortified milk), the body must then convert it into a usable form, called 1,25-dihydroxyvitamin D. This conversion process, however, seems to be short-circuited among obese people, complicating efforts to gauge their true vitamin D health

Because vitamin D levels did not correlate properly with 1,25-dihydroxyvitamin D levels (and in fact appeared to have an abnormal inverse relationship), the authors suggested that future efforts to explore vitamin D status among obese people should test for both measures of vitamin D health.


The researchers concluded that people who are overweight and obese might benefit from vitamin D supplementation and more exposure to sunlight

Junk Food Is Addictive

Junk food can be as addictive as cocaine. Rats given unlimited access to healthy foods and high-calorie snacks quickly developed a preference for the snacks and became obese. The obese rats also had decreased levels of a dopamine receptor that provides a feeling of reward—similar to that reported in humans addicted to nicotine, cocaine and other drugs.

Added Fiber Can't Beat The Real Thing

Added fiber does not have the same effect in the body, according to Arthur Agatston, MD, author of the South Beach Diet books.

Self-defense: Read food labels to find out how much total dietary fiber is listed-then look at the ingredients list to see where the fiber comes from. Avoid foods that include fiber additives, such as inulin, maltodextrin and other unnatural-sounding ingredients.

Better: Choose fresh fruits and vegetables, whole grains and legumes, which are naturally high in fiber. If you are too busy to eat properly, consider a fiber supplement derived from natural psyllium husk.

Fix Flavorful Foods—Without Salt

To make food taste better without adding fat or salt: Use citrus-lemons, limes and oranges—to bring out food flavors. Cook with herbs—then sprinkle on fresh herbs just before serving. Try unusual spices, such as cumin and cloves—alone or in combination to produce varied flavors. If a salad dressing or cooking liquid tastes a little flat, add dried or fresh herbs to the dressing as well as an acid, such as lemon or vinegar, to brighten the cooking liquid.

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