Charles Weber also says there is a connection between potassium and B1 status to be careful of!
He says:
Insufficient potassium and vitamin B-1 (thiamin) can not damage the heart significantly when both are deficient. This has very important implications when supplementing each during heart disease, hypertension, diabetes, and rheumatoid arthritis.
INTRODUCTION
Cardiovascular disease remains as the #1 cause of mortality. About 50% of heart failure patients will perish in 5-years. At age 40, life time risk of developing heart failure is 1 in 5.Diastolic dysfunction heart failure prevalence has increased to 50% of all heart failure. Most of the heart disease in western societies is probably either caused by or is greatly enhanced by a potassium deficiency. Potassium has been used in heart disease therapy since 1930 [1]. Potassium enriched table salt almost halved the mortality from cardiovascular disease of retired men studied in China over a 31 month period [2]. Permanent damage can be inflicted on the heart and kidneys of animals by potassium restriction [3].
However it is possible for a dangerous imbalance with respect to thiamine (vitamin B-1) can arise from potassium supplements if animal experiments are an indication. If potassium supplements are given during the wet heart disease of beri beri (vitamin B-1 deficiency), the heart disease is made much worse [4][5]. Wet heart disease of beri-beri is impossible if potassium is also deficient [6]. Instead a muscular atrophy similar to that from vitamin E deficiency appears [7][8]. Hove and Herndon suspect that muscular dystrophy is a potassium deficiency since body potassium is low during muscular dystrophy [7]. During a vitamin B-1 deficiency the heart loses potassium [4]. This may be why heart damage in beriberi resembles that in a potassium deficiency. The chemistry of vitamin B-1 in the body is extremely complicated and determining its status by chemical tests is very difficult (this article shows the chemistry in great detail)[36 Wooley]. One symptom of a vitamin B-1 deficiency is lactic acid acidosis [9]. Why the heart should be protected by a deficiency of both potassium and vitamin B-1 is strange, and I know no explanation for it.
Some of the symptoms of heart disease are shortness of breath, swelling of the legs and ankles and occasionally the abdomen, fatigue and weakness, loss of appetite and nausea, reduced urination, and persistent cough which sometimes produces mucus or blood tinged sputum.
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He says also:
It is obvious that if potassium supplements are given, it is very important that the vitamin B-1 intake must be adequate at the same time, and one third of heart disease patients are deficient in thiamin [34].
He later says that many things can destroy B1, including blueberries, tannins in tea, and sulfites. He also says "A folate deficiency prevents thiamin absorption in rats." ( Howard L Wagner C Schenker S 1974 Malabsorption of Thiamin in Folate-deficient Rats, J. Nutr.)