March 29, 2016

Are You Getting These Nutrients? - Part 2

The first nutrient thiamin (vitamin B1) is important for the body's energy production, the brain, and the nervous system function. Because it works in concert with the other B vitamins, a deficit of one can cause the others to not function as well. Thiamin is prone to destruction in food processing, storage, and cooking.

Low-Carb Sources of Thiamin
Pork - 4 oz. (before cooking) - almost 1 mg thiamin
Macadamia Nuts - 1 oz. - .34 mg thiamin, 1.5 grams net carb
Chicken Livers - 3.5 oz. - .31 mg thiamin, 1 gram carb
Pecans - 1 oz. - .19 mg thiamin - 1 gram net carb
Peanuts - 1 oz. - .18 mg thiamin - 2 grams net carb
Flaxseed - 1 Tablespoon - .17 mg thiamin, almost zero net carb
Asparagus - 6 medium spears - .14 mg thiamin, 2 grams net carb

Daily recommendations for dietary vitamin B1, according to the National Academy of Sciences, are as follows:
  • Men, 19 years and older: 1.2 mg (RDA)
  • Women, 19 years and older: 1.1 mg (RDA)
  • Pregnant or breastfeeding women: 1.4 mg (RDA)
Most foods contain small amounts of thiamine. Large amounts can be found in: pork, beef, poultry, and organ meat.

As with all medications and supplements, check with your doctor before giving vitamin B1 supplements to a child.

Low plasma concentrations and high renal clearance of thiamin have been observed in diabetic patients compared to healthy subjects, suggesting that individuals with type 1 or type 2 diabetes mellitus are at increased risk for thiamin deficiency. Two thiamin transporters, thiamin transporter-1 (THTR-1) and THTR-2, are involved in thiamin uptake by enterocytes in the small intestine and re-uptake in the proximal tubules of the kidneys. A recent study suggested that hyperglycemia in diabetic patients could affect thiamin re-uptake by decreasing the expression of thiamin transporters in the kidneys. Conversely, thiamin deficiency appears to impair the normal endocrine function of the pancreas and exacerbate hyperglycemia.

In a randomized, double-blind pilot study, high-dose thiamin supplements (300 mg/day) were given for six weeks to hyperglycemic individuals (either glucose intolerant or newly diagnosed with type 2 diabetes). Thiamin supplementation prevented any further increase in fasting glucose and insulin levels compared with placebo treatment but did not reduce the hyperglycemia. However, one study suggested that thiamin supplementation might improve fasting glucose levels in type 2 diabetics in early stages of the disease (i.e., pre-diabetes or early diabetes).

Thiamine comes in tablets to take by mouth. It is usually taken three times a day with meals. If you have a thiamine deficiency, your doctor may prescribe thiamine for 1 month or more. Follow the directions on your prescription label or package label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take thiamine exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Thiamine should be taken with meals. If you are taking an extended-release (long-acting) product, do not chew or crush the tablet. Some tablets can be crushed and mixed with food.

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