Like all of the B vitamins, thiamine is water-soluble, which means that it dissolves in water. It contains derivatives of both sulfur and phosphate.

The Reference Dietary Intake, or RDI (the newer term that replaced recommended daily allowance, or RDA), for thiamine is 1.5 mg per day.

All living things depend on thiamine. Severe deficiency can lead to a condition called beriberi.

Thiamine deficiency can cause neuropathy of the peripheral, central, and optic nerves leading to burning and tingling of the extremities. Thiamine deficiency can also manifest as:

• Confusion

• Fatigue

• Heart attack

• Heart failure

• Irritability

• Weight loss

For more than 20 years, I have been checking patients’ thiamine levels. I can state, without any doubt whatsoever, that thiamine deficiency is alive and well in the 21st century.

In fact, approximately 33 percent of patients have low thiamine levels — and most are severely deficient.

Thiamine is found in whole grain food products, but not in refined grain. Therefore, any food made from processed grain will lack thiamine. This includes refined cereals, breads, and pastas.

Thiamine aids in the treatment of Alzheimer’s disease,1 and I have also found it very effective for those suffering with heart failure.

In many patients with heart or neurological diseases, intravenous, subcutaneous, and intramuscular injections of thiamine have proved very helpful.

Oral doses of thiamine are also effective for most people who suffer from deficiency.

One of my patients, Joe, was diagnosed with congestive heart failure three years ago. At that time, he was placed on cardiac medications, including beta blockers, diuretics, and ACE inhibitors.

When he came to me he was feeling awful. His biggest complaint was fatigue.

“I’m tired all the time, from the minute I get up until I go to sleep. I wish I had more energy,” he said.

When I did Joe’s blood work, his thiamine level was below the detectable limit — near zero. I had Joe take weekly intravenous injections of thiamine as well as supplementing with an oral dose of 50 mg per day, and biweekly subcutaneous injections of 1 mg per dose.

In four weeks, he was feeling better. Oral or injectable, it didn’t matter — thiamine gave him a boost.

Joe’s story isn’t unusual. In fact, it’s the norm.

I have seen few side effects with thiamine therapy. It can be taken with other supplements and is best taken with food, though it’s okay to take it on an empty stomach.