Stents, defibrillators, and other profit-making opportunities

As a practicing cardiologst, every day I receive a dozen or more magazines or newspapers targeting practicing physicians, not to mention the hundreds of letters, postcards, invitations to "talks", etc. that I receive. All of these materials share one common goal: To get the practicing cardiologist/physician to insert more of a manufacturer's stents, defibrillators, prescribe more of their drugs, etc.

This is a highly effective and profitable area. Pfizer's Lipitor, for instance, generated $12.2 billion just last year alone. This kind of money will fund an extraordinary amount of marketing.

I'm on the www.heart.org mailing list, a website for cardiologists. I'd estimate that 90% or more of their content is device-related: discussions of situations in which to insert stents, the expanding world of implantable devices, the ups and downs of various drugs. Rarely are discussions of healthy lifestyles, exercise, nutritional supplements, part of the dialogue.

How can you protect yourself from the brainwashed physician, flooded with visions of all the devices he can put in you, all the drugs that can "cure" your disease? Simple: information. Be better informed. Ask pointed questions. The idiotic lay press tells you to ask a doctor about his education. That's not generally the problem. Some of the best educated doc's I know are also the most flagrantly guilty of profiteering medicine.

Ask your doctor about his/her philosphy about the use of medications, devices, etc. If their word is God, take it or leave it, run the other way.

Will radiation kill you?

Several people have asked me lately if radiation is truly dangerous. These conversations were sparked by an editorial comment made on a column I wrote for Life Extension Magazine's April, 2006 issue on "Three ways to detect hidden heart disease".

Among the methods that were discussed in this piece was, of course, CT heart scanning. Anyone who is involved with CT heart scans Quickly recognizes the spectacular power of this test to uncover hidden, unsuspected heart disease, literally within seconds. In 2006, there's really nothing like it for the every day person to have hidden heart disease detected and precisely quantified.

Yet, the "rebuttal" to my article claimed that the broad use of heart scans was only my personal view and that, in truth, radiation kills people.

NONSENSE! If an ovarian cancer is discovered by a CT scan of the abdomen, is that unwise use of radiation? If pneumonia or lung cancer is discovered on a chest x-ray with minimal radiation exposure, have we performed a disservice. Of course not. In fact, these are often lifesaving applications of radiation.

Can radiation be used unwisely with excessive exposure? Of course. The 64 slice CT angiograms are just an example of this. Dr. Mehmet Oz announced on Oprah recently that this was a test to be used for broad screening of women for heart disease. This is wrong. The radiation required for a full 64 slice CT angiogram test is truly excessive for a screening application. You wouln't want to get breast cancer from your mammogram, would you? The radiation from a 64-slice CT angiogram is similar to that of a heart catheterization in the hospital--too much for screening. This is not to be confused with a CT heart scan for a calcium score performed on a 64 slice device. I think this can be performed with acceptable radiation exposure.

Think about what would happen, for instance, if you had your heart disease undetected, had a heart attack, and went to the hospital? During your hospitalization, you'd likely get five chest x-rays, a heart catheterization, perhaps one or more nuclear imaging tests, maybe even a full CT scan (with far more radiation than a screening heart scan). The amount of radiation of a heart scan is trivial compared to what you obtain in a hospital.

So take it all in perspective. The low level of radiation required for a simple heart scan (not an angiogram) does not by itself substantially add to your lifetime risk of radiation exposure. It may, in fact, save your life or reduce your life long exposure to radiation.

Are you using bogus supplements?

I consider nutritional supplements an important, many times a critical,part of a coronary plaque control program.

But use the wrong brand or use it in the wrong way, and you can obtain no benefit. Occasionally, you can even suffer adverse effects.

Take coenzyme Q10, for instance. (Track Your Plaque Members: A full, in-depth Special Report on coenzyme Q10 will be on the website in the next couple of weeks.) Take the wrong brand to minimize the likelihood of statin-related muscle aches, and you may find taking Lipitor, Zocor, Crestor, etc. intolerable or impossible. However, take a 100 mg preparation from a trusted manufacturer in an oil-based capsule, and you are far more likely to avoid the inevitable muscle aches. (Though, of course, consult with your doctor, for all it's worth, if you develop muscle aches on any of these prescription agents.)

Unfortunately, you and I often don't truly know for a fact if a bottle from the shelf of a health food store or drugstore is accurately labeled, pure, free of contaminants, and efficacious.

One really great service for people serious about supplements is the www.consumerlab.com website. They are a membership website (with dues very reasonable) started by a physician interested in ensuring supplement quality. Consumer Lab tests nutritional supplements to determine whether it 1) contains what the label claims, and 2) is free of contamination. (I have no reason to pitch this or any other site; it's just a great service.) They recently found a supplement with Dr. Andrew Weil's name on it to have excess quantities of lead!

What Consumer Lab does not do is determine efficacy. In other words, they do a responsible job of reporting on what clinical studies have been performed to support the use of a specific supplement. However, true claims of efficacy of supplement X to treat symptom or disease Y can only come with FDA approval. Supplements rarely will be put through the financial rigors of this process.

If you're not a serious supplement user, but just need a reliable source, we've had good experiences with:

--GNC--the national chain
--Vitamin Shoppe--also a national chain
--www.lifeextension.com or www.lef.org--A great and low-priced source, but they do charge a $75 annual membership that comes with a subscription to their magazine, Life Extension (which I frequently write for) and several free supplements that you may or may not need. Again, I'm not pitching them; they are simply a good source.
--Solgar--a major manufacturer
--Vitamin World
--Nature's Bounty
--Sundown

There are many others, as well. Unfortunately, it's only the occasional manufacturer or distributor that permits unnacceptable contamination with lead or other poisons, or inaccurately labels their supplement (e.g., contains 1000 mg of glucosamine when it really contains 200 mg). I have not come across any manufacturer/distributor who has systemtically marketed uniformly bad products.

It really helps to have someone to lean on

Among my patients are several husband and wife teams, both of whom have heart disease by some measure. Several couples, for instance, consist of a huband who's received a stent, survived a heart attack, or has some other scar of the conventional approach. The wives generally have a substantial heart scan score in the several hundred range.

There are a few couples for which the roles are reversed: wife with bypass, heart attack, etc. and husband with a substantial quantity of coronary plaque by CT heart scan.

From them all, however, I've learned the power of teamwork. When both wife and husband (or even "significant other") are committed to the effort of controlling or reversing heart disease risk, the likelihood of success is magnified many-fold. Everything is easier: shopping for and choosing foods, incorporating supplements in the budget, taking vacations with a healthy focus, following through and sticking with your program.

Several of the couples have succeeded in obtaining regression of plaque for both man and woman. Both have reduced their heart scan scores and, as a result, dramatically reduced the potential for future heart attack and procedures.

Unfortunately, I will also see the opposite situation: One spouse committed to the program but the other indifferent. They may say such things as "You can't control what happens in the future." Or, "There's no way you can get rid of risk for heart disease. My doctor says it's hereditary." Or, "I've eaten this way since I was a kid. I'm not changing now for you or for anybody else."

Such negative commentary can't help but erode your commitment to health. Most of us recognize these sorts of comments as self-fulfulling and self-defeating.

What should you do if you have an unsupportive partner? Not easy. But it really can help to seek out a supportive partner, whether it's a friend, relative, or other significant person in your life. Of course, not everybody can find such a person. Perhaps that's another way our program can help.

I'd like to hear from anyone who does obtain substantial support of someone close, or if you are struggling to do so.

Five foods that can booby trap your heart disease prevention program

There are several foods that commonly come up on people's lists of habitual foods that are truly undesirable for a heart disease prevention program. Curiously, people choose these foods because of the mis-perception that they are healthy. My patients are often shocked when I tell them that they are not healthy and are, in fact, detrimental to their program.

I'm not talking about foods that are obviously unhealthy. You know these: fried foods, greasy cheeseburgers, French fries, bacon, sausage, etc. Nearly everyone knows that the high saturated fat content, low fiber, and low nutritional value of these foods are behind heart disease, hypertension, and a variety of cancers.

I'm talking about foods that people say they eat because they view them as healthy--but they're not.

Here's the list:

1) Low-fat or non-fat salad dressings--Virtually all brands we've examined have high-fructose corn syrup as one the main ingredients. What does high fructose corn syrup do? Triggers sugar cravings, makes your triglycerides skyrocket (causing formation of abnormal lipoproteins like small LDL), and causes diabetes. The average American now ingests nearly 80 lbs of this evil sweetener per year. You're far better off with olive, canol, grapeseed, or flaxseed based salad dressings.

2) Breakfast cereals--If you've been following these discussions, you know that the majority of breakfast cereals are sugar. They may not actually contain sugar, but they contain ingredients that are converted to sugar in your body. They may be cleverly disguised as healthy--Raisin Bran, Shredded Wheat, etc.

3) Pretzels--"A low-fat snack". That's right. A low-fat snack that raises blood sugar like eating table sugar from the bowl.

4) Margarine--Forget this silly argument about which is worse, butter or margarine. Which is worse, strychnine or lead? Both are poisons to the human body. Who cares which is worse? Fortunately, there are now healthy "margarines" like Smart Balance and Benecol that lack the saturated fat or hydrogenated fat of either.

4) Bananas--Bananas are not all that intrinsically unhealthy. The problem is that people will say to me, "Oh sure, I eat fruit. Two bananas a day." What I hear is "I don't really eat fruit with high nutrient value, fiber, and reduced sugar release. I reach for only bananas which yield extreme sugar rises in my blood and are low fiber." Aren't they high in potassium? Yes, but there are better sources. Cut back if you are a banana freak.


Why the mis-perceptions? A holdover from the low-fat diet days and marketing from food manufacturers are the principal reasons. Of course, foods are meant to be enjoyed, but be informed about it. Choose foods for the right reasons, not because of some cleverly-crafted marketing campaign.

Breakfast of champions?

I spend time every day educating or reminding patients that breakfast cereals are not health foods.

I see jaws drop in shock when I tell them that, in my opinion and despite the marketing claims, Cheerios, Raisin Bran, Shredded Wheat, and the like do not yield health benefits. In fact, they do the the opposite: dramatically raise blood sugar and trigger an adverse cascade of events that eventually leads to diabetes and heart disease.

Why the health claims in advertising? Because these products contain insoluble fiber, the sort that makes your bowels regular. Yes, your bowels are important to health, too. But the benefits end there.

Breakfast cereals are a highly refined, processed food that are not good for your plaque control program. What they are is a highly profitable, multi-billion dollar business, deeply entrenched in American culture ("They'rrrre grrrrrreat!"--Tony the Tiger; "There's a whole scoop of raisins in every box of Post Raisin Bran!" Bet you remember them all.)

I find it particularly upsetting when I see the stamp of approval from the American Heart Association on some products. Gee, if the Heart Association says it's good for you, it must be true! Don't you believe it. The American Heart Association relies on corporate donations, just like any other charity.

If you must eat breakfast cereals, refer to www.glycemicindex.com for a full database of glycemic inde Cureality | Real People Seeking Real Cures

Unexpected effects of a wheat-free diet

Wheat elimination continues to yield explosive and unexpected health benefits.

I initially asked patients in the office to eliminate wheat because I wanted to help them reduce blood sugar and pre-diabetic tendencies.

A patient would come to the office, for example, with a blood sugar of 118 mg/dl (in the pre-diabetic range) and the other phenomena of pre-diabetes or metabolic syndrome (high blood pressure, high inflammation/c-reactive protein, low HDL, high triglycerides, small LDL), and the characteristic wheat belly. Eliminate wheat and, within three months, they lose 30 lbs, blood sugar drops to normal, blood pressure drops, triglycerides drop by several hundred milligrams, HDL goes up, small LDL plummets, c-reactive protein drops.

People also felt better, with flat tummies and more energy. But they also developed benefits I did not anticipate:

--Improved rheumatoid arthritis--I have seen this time and time again. Eliminate wheat and the painful thumbs, fingers, and other joints clear up dramatically. Many former rheumatoid sufferers people tell me that one cracker or pretzel will trigger a painful throbbing reminder that lasts a couple of hours.

--Improved ulcerative colitis--People incapacitated with pain, cramping, and diarrhea of ulcerative colitis (who are negative for the antibodies for celiac disease) can experience marked improvement. I've seen people be able to stop all their nasty colitis medications just by eliminating wheat.

--Reduction or elimination of irritable bowel syndrome

--Reduction or elimination of gastroesophageal reflux

--Better mood--Eliminating wheat makes you happier and experience more stable moods. Just as wheat is responsible for a subset of schizophrenia and bipolar illness (this is fact), and wheat elimination generates dramatic improvement, when you or I eliminate wheat, we also experience a "smoothing" of mood swings.

--Better libido--I'm not sure whether this is a consequence of losing a belly the size of a watermelon or improvement in sex hormones (esp. testosterone) or endothelial responses, but more interest in sex typically develops.

--Better complexion--I'm not entirely sure why, but various rashes will oftetion

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hunger that eventually overcomes any effort. A period of overeating typically follows the aborted attempt.

Fasting cannot work as long as the 2-hour cycle of hunger continues. The first step: Eliminate the 2-hour cycle of hunger by dramatically reducing or eliminating carbohydrates. Our preferred method is to eliminate wheat, cornstarch, and sugars. (Just be aware of wheat withdrawal, the fatigue that develops in the first 5 days after wheat elimination that affects up to 30% of people.)

Once wheat, cornstarch, and sugars are eliminated, hunger reverts to that of physiologic need--appetite will be smaller and less intense, since it is driven by your body's needs, not by abnormal stimulation from wheat, cornstarch, and sugar. The fear of not having food dissolves, the 2-hour cycle of mental fogginess, fatigue, and hunger will be gone.

Intermittent fasting is a wonderful strategy for reducing weight; gaining control over lipids, lipoproteins, and coronary plaque; regaining appreciation for food; reducing appetite. But it's not even worth trying unless you've already eliminated the unnatural appetite triggers that will booby-trap any fasting effort.

Test your own thyroid

134 people responded to the latest Heart Scan Blog poll:


When I ask my doctor to test my thyroid, he/she:

Accommodates me without question 45 (33%)

Questions why, but orders the tests 49 (36%)

Refuses because you seem "healthy" 20 (14%)

Refuses without explanation 4 (2%)

Ridicules your request 16 (11%)



That's better than I anticipated: 69% of physicians complied with this small request. After all, you're not asking for major surgery. You're just asking for a very basic test, as basic as a blood count or electrolytes. 36% of respondents said that their doctor asked why, but still complied; this is simply practicing good medicine--If there is a problem, your doctor would like to know about it.

However, the remainder--31%--were refused in one way or another. Incredibly, 11% were ridiculed.

Although this was not asked in the poll, I believe that it is a safe assumption that you asked with good reason: you're abnormally fatigued, you have been gaining weight for no apparent reason or can't lose weight despite substantial effort, or you feel cold at inappropriate times.

Let's say you're tired. Ever since last summer, you've suffered a gradual decline in energy.

So you ask your doctor to assess your thyroid. He refuses. "You're just fine! There's nothing wrong with you."

You disagree. In fact, you are quite convinced that there is something physically wrong. What do you do?

You could:

--Drink more coffee
--Exercise more in the hopes that it will snap you out of your lethargy
--Sleep more
--Take stimulants of various sorts

Or, you could get your thyroid assessed and settle the issue. But how can you get this done when your doctor won't accommodate you, even though you have perfectly fine health insurance and are simply interested in feeling better and preserving your health?

You could test your thyroid yourself. This is why we're making self-testing kits available. Test kits are available here.

This is yet another facet of the powerful revolution that is emerging: Self-directed health.

Trains, planes, and heart scans

A Heart Scan Blog reader posted the following question:

It is not clear to me why getting a cardiac scan is the necessary first step, if in fact the next step would be to bring down small LDL particles which is revealed on a NMR lipoprofile or VAP test. Why isn't the NMR or VAP test the first thing?

Good question. Think of it this way:

Lipoproteins, as measured via VAP (Vertical Auto Profile) or NMR (Nuclear Magnetic Resonance), provide a snapshot of risk from a metabolic viewpoint at that moment. Lipoproteins shift with the tides of age, menopause, weight changes, even what you ate last evening for dinner (especially small LDL). There are also other factors that cause coronary plaque, as well, not revealed through lipoprotein testing, such as vitamin D deficiency, smoking, high blood pressure, phosopholipase A2, lipoprotein(a), inflammatory factors, thyroid dysfunction, omega-3 fatty acid deficiency, etc.

A heart scan, providing a coronary calcium score, provides an indirect measure of coronary plaque that is the sum total of lipoprotein and other plaque-causing factors that have accumulated up to the time of your scan--regardless of the cause.

It means that two females, each 60 years old, with 70% small LDL, HDL 42 mg/dl, triglycerides 150 mg/dl, and mild hypertension, have identical markers for potential coronary risk, but can have widely different heart scan scores. One might have a score of zero, while the other might have a score of 300.

Why would the same panel of causes measured at one moment yield wildly different quantities of plaque? Several reasons:

1) The lifestyles, eating habits, and weight of each woman differed during their earlier years, not currently reflected in this moment's lipid or lipoprotein patterns. Perhpaps one experienced several years of extraordinary stress from a failed marriage, or suffered through two years of depression that caused her to smoke and overeat.

2) There are hidden factors that affect coronary plaque growth that we are presently not able to detect, e.g., vitamin D receptor genotype, cholesteryl-ester transfer protein variants, variation in inflammatory factors. If we can't measure it, we won't know whether it might influence coronary plaque risk.


With all the changes that occur over a person's life, with the uncertainties of yet-to-be-identified causes for coronary plaque, how can you possible know what your risk for heart disease truly is? Yup--a heart scan. Do it and you will know.

D2 and D3 are two different things

Helena posted this instructive comment in response to the Heart Scan Blog post, Weight loss and vitamin D. It illustrates the confusion common among physicians and pharmacists on the differences between D2 and D3.

(Edited slightly for clarity.)

Not many weeks ago a colleague of mine (let’s call him Eric) asked me if I knew the difference between D2 and D3 and I told Eric that D2 comes from irradiated mushrooms and D3 comes from wool. In other words, D3 is the same kind of vitamin as humans get from the sun. Humans just don’t get enough and we can’t produce it on our own, like the sheep can. (D3 is natural for humans, D2 is not.)

After telling Eric this, he asked me how he would know what he is taking and I gave him the medical definitions of them both (D2 = Ergocalciferol; D3 = Cholecaliciferol). Since I was aware that he had gotten his Vitamin D by prescription, I told him “I am 99.9% sure that you are taking D2, but I would be thrilled to find out I am wrong.”

Eric called his pharmacy right away and got the answer I was expecting: ergocalciferol. On confronting the person Eric was talking to, the answer he got back was that Ergocalciferol is the only Vitamin D they are giving out.

A week later, Eric had a new appointment with his doctor and decided to ask him about the D2/D3 issue. The doctor said he knew that there was a difference in them both, but could not say what, not even the basic facts I mentioned above. But the doctor stamped a post-it with what he had sent to the pharmacy just to show Eric. “Vitamin D3; 50,000IU tab” is what the stamp said.

Eric, off course, got confused and was starting to believe that the pharmacy had made a mistake by giving him Ergocalciferol (D2) since the doctor had given him D3, or at least that is what was stamped on the little note he had.

Today, after getting a refill of his Vitamin D he also got and kept all his paperwork that came along with it. Still believing that stamp the doctor had given Eric earlier, he asked me to double and triple check that my definition of D2 and D3 was correct. I did, just for my own sanity, and I was still right.

One of the sheets Eric brought me today was the “Patient Education Monograph” sheet stating the drugs and how to use it and so on. The thing that jumped out the most to me was this:

Generic Name: Vitamin D – Oral
Common Brand name(s): Drisdol, Maximum D3
Identification: PA140 Green Oval Capsule

This is the Drug Eric was given: Vitamin D 1.25 MG softgel; Generic name: Ergocalciferol

My researching mind went into high concentration mood and I started to dig. And this is what I found:

The brand name Drisdol is Ergocalciferol (D2), not D3. The Brand name Maximum D3 seems to be hard to find out there in cyber space as a brand name. But the ones I found that were called Maximum D3 seems to be the real stuff, however none of them required a prescription.

When trying to find out through the identification number on the pills (PA140) I now know for sure that Eric is taking Vitamin D2 and not the preferred Vitamin D3. The brand name, Drisdol, had the identification W on one side and D92 on the other, but it is still Ergocalciferol.

The only conclusion I can draw from all this is that the medical industry does not know or care about the difference in D2 and D3 – it is all same to them. And as long as the pharmacies only give out D2 it does not matter what the doctor prescribe anyway.

I know that people are most likely to be prescribed a D2 pill than to be told to buy over-the-counter D3. But it was almost heart breaking to see the letter D and number 3 right next to the drug Drisdol, as we know is a D2 vitamin. It just didn’t make sense to me that they can be labeled as the same type of medication, when we know it is not!



Incredible.

Why prescribe plant form D2 when you can get perfectly reliable, safe, effective D3--the human form, at the health food store for about $6?

Once again, it's the peculiar false bias of physicians and pharmacists: If it's prescription, it must be good; if it comes from a health food store, it must be bogus.

Humans need human vitamin D. Plain and simple.

For more on the D2 vs. D3 issue, see the Heart Scan Post, The case against vitamin D2.

Weight loss: Different causes, different solutions

Heart Scan Blog reader, Kris, related this enlightening story of weight loss (slightly edited for clarity).

Kris learned that excess weight is gained through multiple causes. The solutions are therefore multiple, not just one change in diet or two.


I started studying about my thyroid issue much earlier and did lose some weight. But ever since I started following Dr. Davis’s blog, it has given me confidence that I was on the right track. I did have my thyroid and iodine figured out from other sources, but Dr. Davis helped me to understand the issues with not only the thyroid but vitamin D3, fructose, fish oil, niacin, wheat etc. I have lost 43lb in last 14 months.

It seems to me that there are certain percentages of weight connected with different issues. For example, after I gave up alcohol and sugar, I lost about 14lbs from total weight of 243lbs, weight came down to about 229lb. Then it stopped at 229lb, even though I was in the gym almost 5 to 6 days a week with full workouts.

After I changed my thyroid medication to natural thyroid hormones (took synthetic T4 for over 10 years), the weight dropped down further 13lbs or so in matter of few days, shape of the face changed from moon shape/double chin to ordinary long face. Then it kind of stopped at around 213-216 lbs.

After giving up wheat, reducing carbs, increasing protein intake (whey protein, chicken etc. no soya, no fructose) the weight came down another 14lbs. Now it is around 200-202lbs and I am over 6.2 tall with heavy set of bones.

I feel better than I have ever in my life. More stamina, more clarity/no fog, more confidence and 99% of the time relaxed and being able to see the situation from multiple angles.

I use to be able to drink a liter or more jack denial without a problem in one evening but now can’t stand half a can of beer (I miss JD). Drinking alcohol makes me sick. I sleep well and if I wake up in the middle of the night, I have no problem going back to sleep. No more out of breath stair climbing at all.

One other thing: I used to be the most attractive meal to the mosquitoes, but not anymore. This year I haven’t been bitten once. I take my dog to the park everyday and I do not use any mosquito repellent, what a relief. I don’t know if it is because of thyroid, iodine, wheat or something else. Skin texture has changed dramatically. I do not use full soap or shampoo, 20% borax, 10 percent of my soap or shampoo for scent and rest water, mixed in a 500ml bottle. No more dandruff, dry skin, pimples for me.

Dr. Davis I am thankful to people like you who have the ability to see beyond what you have been taught and have the guts to say the way it is. Most of us work to make living on daily basis but some make their living while spreading their knowledge to save lives. Dr Davis you are one of those few people. Please keep it going.

Calling all losers!

I'd like to invite anyone who has followed the Track Your Plaque Break the Weight Barrier program to consider posting their stories and photos on the Heart Scan Blog.

Because our focus is prevention and reversal of coronary heart disease, we have not made an effort to catalog the weight loss experience that people have while on the program. For many, weight loss has been substantial. (Several people this week alone have reported weight loss of 9 to 46 lbs in the past 6 months.)

It would be helpful to hear and see these results.

For those of you who don't mind having a story and photo on this Blog, please come back in future to post your results. You will find this post by entering "weight loss" into the site-specific search bar at the top of the page.

Weight loss and vitamin D

At the start of her program, Penny's 25-hydroxy vitamin D blood level showed the usual deficiency at 22 ng/ml.

She supplemented with 8000 units of vitamin D. Another 25-hydroxy vitamin D blood level several months later showed a level of 67.8 ng/ml, right on target.

But Penny also began our diet, including the elimination of wheat, cornstarch, and sugars, and, over 6 months, lost 34 lbs.

Now a much trimmer 146 lbs (still more to go!), another vitamin D blood level: 111 ng/ml.

Penny's weight loss means that the vitamin D is distributed in a smaller total volume, particularly a lower volume of fat.

This is a common phenomenon with substantial weight loss: lose weight and the need for vitamin D is reduced. The reduction in dose is roughly proportion to the weight lost. Vitamin D should therefore be reassessed with any substantial change in weight of, say, 10 lbs or more, either up or down, because of the influence of fat on vitamin D blood levels.

Some references on this effect:

Men and women over age 65:
Adiposity in relation to vitamin D status and parathyroid hormone levels: a population-based study in older men and women.

Obese women:
Low 25-hydroxyvitamin D concentrations in obese women: their clinical significance and relationship with anthropometric and body composition variables

Obese children:
Hypovitaminosis D in obese children and adolescents: relationship with adiposity, insulin sensitivity, ethnicity, and season.

African-Americans:
Relationship of vitamin D and parathyroid hormone to obesity and body composition in African Americans.

Although the bulk of the effect is most likely due to sequestration by fatty tissue, perhaps less sun exposure in obese people also contributes:
Body mass index determines sunbathing habits: implications on vitamin D levels.