Vitamin D Kidney Stones

Oliver Gillie has done it again. He is the editor of a free manuscript, Sunlight Vitamin D and Health. This time it is a collection of articles from a conference about vitamin D organized at the British House of Commons in November 2005, chaired by Dr. Ian Gibson, MP. The conference was dedicated to the scientist, Sir Richard Doll, who proved George Bernard Shaw was right when Shaw said, "Progress is impossible without change, and those who cannot change their minds, cannot change anything."

Sir Doll (who researched and wrote about the dangers of cigarette smoking in 1950) had earlier signed off on a British report warning of the dangers of sunlight. Before his recent death, at 92, he changed his mind and became an advocate of responsible sun exposure. Reinhold Vieth once pointed out that the science of the dangers of cigarette smoking and the science of the benefits of vitamin D were quite similar (mostly epidemiological) when governments and physicians began warning about the dangers of smoking. In spite of similar evidence about vitamin D deficiency, no government or organ of medicine is taking the steps necessary to address vitamin D deficiency. After looking at the vitamin D data, Sir Doll said, "This isn't difficult science, we should have answers."

Does vitamin D cause kidney stones?

It may, at least for people on modern American diets. The reason this has come up is because a recent study found the relative risk for people taking 400 units of vitamin D and 1,000 mg of calcium daily was 17% higher than in the placebo group. To my knowledge, this is the first study to find an increased risk of kidney stones with vitamin D supplementation. I'm not aware of any reports of increased incidence of kidney stones in any other vitamin D supplementation trial. N Engl J Med. 2006 Feb 16;354(7):669–83.

The largest study that looked at the risk of kidney stones with vitamin D came out of Harvard. They studied 45,616 men over 14 years for a total of 477,000 person-years of follow up. They found no increased risk of kidney stones with vitamin D intake but did not look at sun exposure or 25(OH)D levels. Of interest, they found three things in your diet that protect against kidney stones: high potassium (46% lower relative risk), high magnesium (29% lower relative risk), and high fluid intake (29% lower relative risk). For younger men, higher dietary calcium was associated with a reduced risk of kidney stones (31% lower relative risk). J Am Soc Nephrol. 2004 Dec;15(12):3225–32.

It seems likely that physiological vitamin D intakes will result in a higher relative risk for kidney stones for people on modern American diets (low potassium, low magnesium, high refined carbohydrates, high sodas, and a high acid residue). You may lower your risk of kidney stones by remaining vitamin D deficient, but then you raise your risk of dying from many other diseases. The best thing to do to prevent kidney stones is be sure you drink adequate fluids, be sure you have adequate magnesium (see below) and potassium in your diet, and be sure you are not in a state of low-grade metabolic acidosis. The last is important, because foods that contain potassium (vegetables and fruit), also turn your body more basic. Eur J Nutr. 2001 Oct;40(5):200–13.

Today, humans live in a state of low-grade metabolic acidosis, mainly caused from a modern diet of high animal protein, refined sugars, refined grain, and sodas—instead of an ancient diet of moderate protein and whole grain and lots of vegetables and fruit. The low-grade acidosis in modern humans leaches calcium from our bones, increases the amount of calcium in our urine, and causes kidney stones, hypertension, and even stroke. Also, vitamin D does not work as well in metabolically acidotic people. For those of you who just can't eat five to nine servings of vegetables and fruit a day, 25 mEq of effervescent potassium bicarbonate every day in the form of a supplement is a good idea, as long as you are not taking a medication (usually for hypertension) that inhibits potassium excretion by the kidney. Semin Nephrol. 1999 Sep;19(5):487–93.

Dr. Cannell, should I use sunscreens or cosmetics that contain sunscreens?

Hundreds of people have asked me this question. It's important to remember that many cosmetics contain sunscreens. My short answer is, "If you are comfortable drinking sunscreens, then you should feel comfortable putting them on your skin." At least three studies have found that the chemicals commonly used in sunscreens are absorbed through the skin and end up circulating in your blood stream. As they circulate in your blood, they go to your internal organs—where they do whatever those chemicals may do there. Then they are excreted in your urine. If you drink them the same thing would happen. Sunblocks that have old style zinc or titanium oxide as their only active ingredients are not absorbed by the skin. Zinc oxide used to be a gooey paste, now it is emulsified, and may, or may not, be absorbed systemically. It blocks light, just like clothes. I remember a beach in France where a beautiful young woman had carefully applied the old gooey red zinc oxide to her body in the shape of a tiny red bikini. She couldn't sit down because the sand would stick to her. She was naked but you had to look twice (which I did) to see just how naked she was. J Invest Dermatol. 2004 Jul;123(1):57–61. J Chromatogr B Biomed Appl. 1996 Jun 28;682(1):137–45. J Chromatogr B Analyt Technol Biomed Life Sci. 2004 Apr 25;803(2):225–31.

Finally, if you think your sunscreen is preventing your skin from turning red just by blocking solar radiation, think again. Sunscreens inhibit an enzyme in your skin that makes nitric acid and one of the functions of nitric acid is to inflame your skin. The inflammation then signals your immune system to start protecting your skin and tells you to get out of the sun. Sunscreens block nitric acid formation, the skin doesn't redden, the immune system isn't notified, you stay longer in the sun, your skin is damaged, and you increase your risk of skin cancer and premature aging. Melanoma Res. 2005 Feb;15(1):3–6.

I call this combination of events—drinking sunscreen and insecticides while blocking your immune system's ability to protect your skin—the "Gilchrest Phenomenon," named after the Chairwoman of Dermatology at Boston University who funds her department with grants from the sunscreen/cosmetic industry.

Dr. Cannell, my dermatologist told me that the sun causes melanoma and I should stay out of the sun. He seems to know what he is talking about.

Sunlight contains radiation. Radiation can both help and harm you. The body figured that out long ago, way before dermatologists evolved. People who lived in the sun, like your ancestors in Africa, did not get sunburned. They were in the sun most of the day so their skin developed a natural sunscreen, melanin, which pigmented their skin black or brown. That pigmentation rapidly disappeared in the humans that migrated to temperate latitudes beginning 50,000 years ago. Today, most light skin people also deposit melanin in their skin on sun exposure; we call it a tan and it has always been a sign of good health. Diets rich in vegetables, fruits, and omega-3 fats—and the absence of appreciable quantities of omega-6 and trans-fats—also protects your skin from burning. The people who get sunburned are modern humans who live and work indoors, avoid fruit and vegetables, love french fries and chips, hate salmon, and go to the beach two or three times in the summer to roast themselves. Frequent sunburns, especially in childhood, are but one factor in melanoma; genetics, and diet are more important. Nutr Cancer. 2000;36(2):155–62. Annu Rev Nutr. 2004;24:173–200.

There is a dermatologist at Rush University Medical Center, Dr. Arthur Rhodes, who understands most of this. If you want to read a reasonable dermatologist, one who has escaped the mass hysteria that all melanomas are caused by sunlight, read his paper on cutaneous melanoma.

The real question is, "Which is best: vitamin D supplements or sun exposure?" The answer is tough. First, the sun won't make much vitamin D during the winter at temperate latitudes above 37 degrees, so if you rely solely on the sun, you'll need to take supplemental vitamin D, use a UVB lamp or a sunbed during the winter. Second, African Americans can't spend an hour in the sun every day so they must take adequate supplements. Third, what other good does the sun do in addition to making vitamin D? The last one is the clincher for me and was recently discussed by Luca and Posonby in the paper below. As humans evolved in the sun, I sensibly go in the sun when I can (without drinking a bottle of Coppertone chased with a bottle of Deepwoods Off). Prog Biophys Mol Biol. 2006 Sep;92(1):140–9.

If you are scientific, try a little experiment. Take someone you know with fair skin who burns easily and who doesn't go in the sun. Take him or her into a sun tan booth and find out exactly how many minutes it takes for their skin to just begin to turn pink, called one minimal erythemal dose (MED). Then, keep them out of the sun but give them 10,000 units of vitamin D a day for a month. Then take them into the sun tan booth again and see how long it takes for them to get one MED. What you will discover is that their time for one MED is longer. High vitamin D blood levels help prevent burning and facilitate tanning. My teenage daughter, who used to burn easily, discovered this. Against my advice, she took 5,000 units of vitamin D every day and regularly went into a sun tan booth as well. Now all her friends are begging her to tell them why she never burned and got so incredibly tan, tanner than she ever got before. Furthermore, burning in vitamin D deficient people actually may have an evolutionary benefit. Burning heats the skin and the final step in the production of vitamin D is driven by high skin temperatures. It also makes evolutionary and physiological sense that high vitamin D blood levels would facilitate rapid tanning and thus protect against vitamin D toxicity. Just remember, burning is dangerous and should always be avoided.

Who is Professor Heidi Cross and why has she been in the news lately?

Dr. Cross is a researcher at the Medical University of Vienna. Recently, she has made the case that the reason people who eat soy products have lower rates of cancer is because one of the components of soy, genistein isoflavone, blocks the enzyme that degrades vitamin D and thus raises tissue levels of activated vitamin D. She makes the case that cancer could not only be prevented, but possibly treated, not only by taking vitamin D, but by manipulating the enzymes that metabolize (build up) and catabolize (break down) vitamin D. It's important to lay persons and non-medical professionals because the substances necessary to do all this, vitamin D and genistein are available without a prescription. I should add that Dr. Cross does not recommend lay people do this on their own, she is making the case for further research. However, if you are fighting a serious cancer, the relative risk of taking 10,000 units of vitamin D and 1,000 mg of genistein every day is quite small compared to your impending death. Future Oncol. 2005 Jun;1(3):415–24.

What's the most interesting recent paper about vitamin D?

Dr. Armin Zittermann has again raised the question that vitamin D deficiency is a major cause of heart disease. He has also recommended 2,000–4,000 units of vitamin D (50–100 mcg) daily for those with heart disease. I find this interesting because my father-in-law has heart disease and hypertension. He has had an irregular pulse, called trigeminy, for several years. He recently agreed to take 200,000 units of vitamin D a day for three days and then maintain himself on 5,000 units a day. Two days after beginning 200,000 units a day his trigeminy disappeared and his blood pressure reverted to normal. A week later, after taking only 5,000 units a day for several days, his trigeminy reappeared. A month after taking 5,000 units a day his trigeminy again disappeared and didn't return and his blood pressure remained improved. There is a case study in the literature describing a woman with long standing cardiac arrhythmia (sick sinus syndrome) that disappeared when she started taking vitamin D for an unrelated condition. Prog Biophys Mol Biol. 2006 Sep;92(1):39–48. Heart Fail Rev. 2006 Mar;11(1):25–33. Geriatrics. 1990 Aug;45(8):83–5.

What role does magnesium play in vitamin D deficiency?

Actually, magnesium and vitamin D have many similarities. Both are dirt cheap. Just like vitamin D, magnesium has been getting a lot of press recently although some experts have been warning for years that magnesium deficiency is rampant and contributes to heart disease. No one really knows how many people are at risk because magnesium blood tests tell you little about magnesium stores, just like an activated vitamin D test tells you little about vitamin D stores. Like vitamin D deficiency caused by health conscious people avoiding the sun and using sunscreens, magnesium deficiency has been made worse by health conscious people avoiding hard water and using water purifiers. Also, just like vitamin D, normal serum levels for magnesium were obtained from deficient patients. Recently, magnesium has been implicated in the vitamin D parathyroid hormone interaction. Many patients with heart disease are both vitamin D and magnesium deficient. Finally, just like the Vitamin D Council, the Magnesium Website—operated by an activist—is trying to spread the word about magnesium deficiency. However, unlike Dr. Cannell of the Vitamin D Council (who is not able to give out free vitamin D), Paul Mason, president of the Healthy Water Association, will give free magnesium rich mineral water to anyone who drives to Adobe Springs, California to pick it up. Dis Mon. 1988 Apr;34(4):161–218. J Am Coll Nutr. 2004 Dec;23(6):730S–1S. Am J Health Syst Pharm. 2004 Aug 1;61(15):1569–76. Osteoporos Int. 2006 Jul;17(7):1013–21.

Another thing to do, if you must use salt, use real salt and not sodium chloride. Many people think salt and sodium chloride are the same thing. They are not. Salt is salt and sodium chloride is sodium chloride. Salt is a complex combination of minerals obtained from the sea or from land deposits left by ancient sea beds. It was a precious commodity in ancient times. Salt has magnesium as well as numerous other trace minerals. Sodium chloride does not. When you buy most salt in the supermarket, you are actually buying sodium chloride, not salt. The Morton company mines salt, takes out the minerals—other than sodium chloride—and sells them separately; then takes what is left and sells that as salt. It's not salt, it's sodium chloride. When you buy salt, buy real salt. Trader Joe's sells sea salt for a low price. Most mineral water, not bottled water, also contains magnesium.

What's the most interesting paper you've come across recently?

A paper by Dr. David Grimes in the July 1st edition of Lancet raised the question that statins may work, not by lowering cholesterol, but by acting as vitamin D analogues. He presented no chemical evidence, only the epidemiological observations that statins and vitamin D seem to have a beneficial effect on the same spectrum of diseases. The most interesting thing about the paper was that it was published in Lancet. Lancet. 2006 Jul 1;368(9529):83–6.

Dr. Cannell, what is the weirdest study you've come across?

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Dr. Cannell Answers More Readers' Questions