Entries by Chet Zelasko

My Verdict on D3 vs. D2: A Draw

The medical community and the health gurus agree, and the research appears to agree with them: vitamin D3 is better than vitamin D2. A no-brainer, it would appear. No. My call at this point: it’s a draw. Here’s why. The Current Research The research on vitamin D and absorption is a mess. There’s little to […]

The Research on Vitamin D3 vs. D2

One area that the medical field and the health gurus agree: vitamin D3 is better absorbed and utilized than vitamin D2. Four studies are constantly referenced when the best type of vitamin D is discussed (1-4); here’s a quick look at those studies. Study 1: 4,000 IU vitamin D3 and D2 supplementation was given to […]

Vitamin D3 vs. Vitamin D2

Many of you have questions about the different forms of vitamin D available in supplement form: vitamin D3, known as cholecalciferol, and vitamin D2, called ergocalciferol. Although they’re slightly structurally different, both have been used for years to help with vitamin D deficiency. Vitamin D is necessary for bone health, of course, but research has […]

Do Fit People Live Longer?

Will being fit help you live longer? Does the improvement to the respiratory, cardiovascular, and muscular systems result in an increase in longevity? Researchers in Austria did a thorough review of the science of fitness to find out. They approached it in the same manner I would: review the systems involved and how aging affected […]

How Long Does Fitness Last?

Does exercise when you’re young have any impact when you’re older? That’s the question researchers sought to answer in a very unique study. They recruited men who competed in running events in the 1968 Olympics and evaluated fitness variables to see how they had changed since then. The subjects were tested in 1993 and retested […]

How Chromium Conflicts with Levothyroxine

In the recent series of Memos on thyroid issues, I explained what you need to know about levothyroxine, the medication prescribed for an underactive thyroid gland. New research highlights a key factor in ensuring its effectiveness. Researchers examined a dietary supplement to see what impact it would have on absorption of levothyroxine. They found that […]

Bioavailability Ends with Bioactivity

Here’s where we stand: we’ve digested a nutrient and it’s been absorbed into the bloodstream. How is it going to be used? How do we get the benefit of vitamin C, magnesium, alpha-carotene, or caffeine? Let’s take a look. Many target cells have receptors that are specific to a nutrient, like a wrench that fits […]

Bioavailability Continues with Absorption

On Tuesday I talked about some of the processing required to get nutrients ready for absorption. The next phase of bioavailability is the absorption of the nutrient from the gut into the bloodstream. Let’s look at what’s involved. The absorption process occurs via the intestinal epithelial cells and they vary in size and function in […]

Bioavailability Begins with Digestion

Last Saturday’s Memo introduced a new concept: a systems approach to nutrition. One term that gets bounced around a lot related to dietary supplements or different types of food is bioavailability. Claims are made that “this form of our supplement is 10 times more bioavailable than that form.” It sounds so simple, right? It’s not—we’ll […]

Why Nutrition Is a Process

A celebrity doctor who specializes in cancer treatment said something that caught my attention, and it goes to this question: why are some people cured by specific treatments while others don’t respond at all? In his opinion, it’s because the cancer creates a new system in the body that competes with the other systems. The […]