Vitamin D Deficiency: Really Guilty of Causing Obesity?

A Well-Known Health Website Gets the Facts About Vitamin D Deficiency and Obesity Totally Wrong

Vitamin D deficiency is linked to depression. Vitamin D deficiency is linked to high blood pressure. Ironically, since human skin makes vitamin D when it is exposed to bright sunlight (with a UV index of at least 4), vitamin D deficiency has even been linked to skin cancer.

And the latest finding of vitamin D research is being reported that deficiency in D may cause obesity. Buy our vitamin D spray and watch the pounds fall off, the article implies. But the relationship being touted in the article isn't what the research said.

What the obesity researchers really discovered, and what they didn't. The website Natural News reported that a research team at the Rikshospitalet-Radiumhospitalet Medical Center in Oslo, Norway, publishing their findings in the Journal of Nutrition, had learned that people who had a higher BMI (body-mass index, a measure of obesity correcting weight for height) had lower levels of vitamin D2 in their bloodstream.

There are two main kinds of vitamin D in the human body. There is vitamin D3, which is what you get in a supplement and what is made by your skin. This is the storage form of the vitamin. There is also vitamin D2, which is activated by your liver for use in cells. Your body typically has about 1,000 times more D3 than D2. It's normal to have a lot more D3 than D2. If you don't, it's usually because of an abnormality in your parathyroid glands.

There was absolutely nothing in the Norwegian research that found that not getting enough vitamin D causes obesity. In fact, the researchers weren't looking at causality at all, and the article didn't even say that there was an important relationship between vitamin D and obesity.

It just said that obesity was one of several factors determining D2 levels. The most important predictor of your active, D2 levels, according to the researchers, is your storage form, D3 levels. Age, gender, time of year, and body mass index also fit into the relationship, but not very strongly. So what is the relationship between obesity and vitamin D levels?

Does Vitamin D Deficiency Really Cause Obesity?

Even if there were a strong relationship between obesity and vitamin D2 levels, and there's not, this wouldn't mean that vitamin D deficiency caused obesity so taking vitamin D supplements would help you lose weight. There would be at least two different ways to understand the data:

1. One would be that low vitamin D levels somehow stuffed fat into your fat cells.
2. The other would be that you didn't like to lie out by the pool so you didn't get as much sun!

Or that you were less able to spend time outdoors, especially in hot, sunny weather, because the heat made you uncomfortable and you didn't get as much sun.

There is one important principle to remember about weight gain. While there are many factors that affect your appetite, and there are many factors that accelerate or decelerate weight gain or weight loss,

You lose weight when you eat less, and you gain weight when you eat more.

If you want to weigh less, chances are you aren't going to be able to exercise enough to make a big difference on the scales. You really will, at some point, have to eat less. The question is how much less.
Will vitamin D help you lose weight faster or gain weight more slowly?

There is some exciting news. Researchers really have answered the question of whether vitamin D helps women lose weight after menopause. A group of researchers at Creighton University Medical Center in Omaha, Nebraska followed 1,179 women for four years, giving them combinations of calcium and vitamin D. One group got Calcium plus a fake vitamin pill. One group got Calcium plus a real vitamin D pill. And one group got two fake supplement pills. All were followed for four years. One group got a boost in weight-loss dieting. Which group was it?

Vitamin D Deficiency Doesn't Cause Obesity. Vitamin D Supplements Don't Cure It

The study at Creighton University found that women who took both calcium and vitamin D lost weight or at least didn't gain as much. The study found that women who took just calcium also lost weight or didn't gain as much, but there was no added benefit to taking vitamin D.

So let's review. The Norwegian study didn't measure causality. It only measured correlation. The Creighton study looked at causality, and found that adding to vitamin D to calcium didn't help. But what about other studies?

There has been one other, similar study, conducted at . It found:

• Women who had low vitamin D levels who took 3,000 IU of vitamin D a day while dieting gained weight.
• Women who had low vitamin D levels who took 5,000 IU of vitamin D a day while dieting also gained weight.
• Women who had healthy vitamin D levels who took 3,000 IU of vitamin D a day while dieting gained weight, but
• Women who had healthy vitamin D levels to start with, who took 5,000 IU of vitamin D a day while dieting, lost an average of 0.2 kilos (about half a pound) in twelve months. However, some women in this group gained as much as 4.7 kilos (10 pounds).

The scientific evidence not only does not find that vitamin D deficiency causes obesity, it even finds that taking vitamin D may cause you to gain weight!

However, that doesn't mean you don't need vitamin D for other aspects of your health. It just means it is not a weight loss wonder, and you will have to eat less to enjoy all the benefits of vitamin D. And beware natural products vendors who sell you weight loss products that actually cause you to gain weight, only so you will want to buy even more.