First of all I would like to thank you for your work and help. Could you tell me, what is the significance of expensive food sensitivity tests based on IgG values? Most people receive a list of dozens of foods to eliminate from their diets without causing them any problems. I think it can lead to develop eating disorders or nutrient deficiencies. What do you think? Thank you so much for your opinion!

Is Mio (water enhancer) bad for you?

I am allergic to peanuts. Does that mean that I am allergic to pecan nuts as well?

I'm curious to know if going to the gym increases sexual drive? I am a female in my 20s and recently started an exercise routine (running and weights), and I have noticed that my sexual drive has increased significantly. There have been no other major changes in my life, and I have been dating the same man for close to two years now, so I can think of no other real reason why my libido would have increased. Is there any real connection between working out in the gym and beneath the sheets?

1) Is it true that eating fat keeps the body warm in cold weather?

2) What I'd like to know is, does my body burn more calories to keep me warm when it's cold out? Thanks!

Once a day, after meals — whenever my roommate isn't around, I stick my fingers down my throat and throw up most of the food that I had just eaten. I do not binge — I only purge. I understand from my Psychology professor that the diagnosis of bulimia nervosa requires that the person binge and then purge. I am curious, then, what I have — do I have a form of anorexia nervosa or what? Also, I am on birth control pills and I am afraid that I might hurt their effect by throwing up. How long does it take for the pill to get absorbed into my system? I usually don't throw up until about 5 or six hours after I have taken the pill. Will this hurt the effect of the pill?

1) Do you recommend any natural remedies (Melatonin, etc.) as dietary supplements for healthy living?

2) I have been seeing a lot of ads on dietary supplements and have been thinking about trying them. However, I'm not sure if it's a good idea. Could you please tell me if the use of dietary supplements is really worth it?

1) What about avocados? I know they don't contain any cholesterol, but they are high in fat so I have avoided them. Now, however, I am reading that the kind of fat they do contain may be useful in lowering cholesterol. Do you have any further information on this?

2) I love avocados and have heard that the different varieties have different health benefits and some are less fattening than others. Please can you tell me about different varieties and which are best.

I recently received an alarming e-mail regarding the dangers of eating Canola oil. Apparently it is made from rapeseed, which is supposedly highly toxic and has been shown to develop cancer in rats. The e-mail also referred me to an article by a Tom Valentine called "The Canola Oil Report." I located the report, read it, and quite frankly, threw out the remaining canola oil I had in the kitchen. Is there any truth to this article? And if there is, surely this is criminal.

I recently had lab work done that identified a vitamin D deficiency. My level was eight and my doctor says that 30 is considered a normal level. I was then prescribed a vitamin D2 pill to help bring my levels up. I just read something that said vitamin D3 is the preferred type to use as a supplement and that 30 isn’t considered the “normal” level anymore, that the number should be closer to 40 or 50.

A few questions: Is it better to use D3 or D2? What level is considered normal? What are the effects of vitamin D deficiency?