Archive for the ‘vitamin C’ Category

Vitamin C Redux

Thursday, January 31st, 2008

A 31-year-old Australian woman who received a kidney transplant with good early graft function later died as a result of calcium oxalate deposits that led to failure of the transplanted kidney. The tragic case, recently reported in the New England Journal of Medicine was attributed to ingestion of 2 grams (2,000 mg.) of vitamin C daily for three previous years while she was on dialysis.

The authors point out that excess ascorbate (Vitamin C) is normally excreted harmlessly in the urine, but in patients with renal failure, it is retained and converted to insoluble oxalate and can accumulate in multiple organs, as is shown vividly in the photographs.

Oxalate-induced kidney failure has also been reported in people with no apparent kidney problem. Oxalates are found in a variety of fruits, vegetables, nuts, and many other foods.

Megadose vitamin C therapy is dangerous and should be avoided.

The Vitamin C Hangover

Tuesday, July 17th, 2007

 

 

Linus Pauling, Nobel Laureate in Chemistry, is ranked in a list of the 20 greatest scientists of all time by the British magazine New Scientist, along with Albert Einstein and Newton. His previous insights about the structure of DNA led to its discovery by Watson and Crick. He is considered a founding father of quantum chemistry and molecular biology. Anticipating over 50 years ago the dangers of air pollution from automobile exhaust, he even built an early electric car!

 

In his late 60’s, Pauling, influenced by the biochemist, Irwin Stone, began taking vitamin C in huge doses, 1000mg.-3000mg every day to prevent and abort colds. Excited by the results, he published “Vitamin C and the Common Cold” in 1970. He then began a long collaboration with the British cancer surgeon, Ewan Cameron in 1971 on the use of vitamin C as cancer therapy for terminal patients. Cameron and Pauling wrote a popular book, “Cancer and Vitamin C.” Pauling’s work on vitamin C generated controversy and was quickly regarded by some adversaries in the field of medicine as outright quackery. Three prospective, randomized, placebo-controlled trials were conducted at the Mayo Clinic; all three failed to prove a benefit for megadoses of vitamin C in cancer patients. Further studies during the following decades convincingly showed that megadoses of vitamin C did not prevent or abort colds, and did nothing for cancer.

With overwhelming medical evidence to the contrary, millions of people still believe in vitamin C, to the tune of hundreds of million dollars in yearly sales. Despite the recommended daily allowance by the Government of 75mg-90 mg./day for adults, (it used to be 30mg./day) enormous numbers of Americans think nothing of dosing themselves with 1,000mg-5,000mg. a day for the treatment of colds. Some cancer patients still believe in the vitamin. Googling vitamin C gets you 40.6 million hits. For starters there’s a Vitamin C Foundation, a pop singer Vitamin C, and in 2000 Mattel released a Vitamin C Doll.

Vitamin C is plentiful in a wide variety of foods, not only fruits and vegetables, but in meats, and many cereal products. It is largely destroyed by cooking; on the other hand it is not stored by the body. Most people tolerate large doses of vitamin C without difficulty, However, overdosing with over 1,000 mg. of Vitamin C can cause nausea, cramps, and diarrhea, and reduce absorption of vitamin B-12, and even cause iron overload. A recent report blames a worsening of osteoarthritis on large doses of vitamin C. Chronic megadoses of vitamin C in some patients may enhance the development of (oxalate) kidney stones.

Spend your health dollar as you will, but if you’re taking excessive doses note that over 95% or more of ingested vitamin C is excreted in the urine in 24 hours. This is literally a way to flush away your money.