08 July, 2011
Sunflower Seeds & B-6 Toxicity
Sunflower seeds are a popular snack among spectators at competitive sporting events, passengers on long car rides or people engaging in any activity that allows mindless chomping. The seeds are commonly sold in the hull, which has a uniquely almond shape and striped coloring.
Nutrition Facts Overview
The term "sunflower seed" is used to describe what is technically considered to be a kernel inside the hull. The hull is not normally eaten and can be split in two parts inside the mouth and spit out, leaving behind the seed kernel. In this article, the nutritional information represents only the sunflower seed kernel.
Vitamin B6 Benefits
Vitamin B6 is essential to the human body, supporting multiple physiological pathways. For example, vitamin B6 helps build red blood cells, which transport oxygen around the body. Sunflower seeds are a good source of vitamin B6. One ounce of sunflower seeds contains 0.228 mg of vitamin B6, which represents 10 percent of the U.S. Department of Agriculture Recommended Daily Allowance for this vitamin. The RDA for vitamin B6 is 1.3 mg for both men and women ages 19 to 50 years.
Vitamin B6 Toxicity
The National Institutes of Health Institute of Medicine reports that vitamin B6 doses of 500 mg a day can result in nerve damage to the arms and legs. This neuropathy is usually related to high intake of vitamin B6 from supplements and is reversible when supplementation is stopped. The Institute of Medicine has established an upper tolerable intake level (UL) for vitamin B6 of 100 mg per day for all adults.
Risk for Vitamin B6 Toxicity
While it may seem plausible to eat 1 lb. of sunflower seeds during a big game or a long drive, even 1 lb. of sunflower seeds contains a level of vitamin B6 nowhere close to the upper tolerable intake level. Given 0.22 mg of vitamin B6 per ounce of sunflower seed kernels, you would need to eat 454 oz. of sunflower seeds, or 28.4 lb.
Sunflower seed kernels are naturally high in calories and fat, and low in sodium. They may be prepared with or without oil and salt, which will change their nutritional profile. Sunflower seeds contain phytosterols, which are suggested to have a cholesterol-lowering effect. The U.S. Department of Agriculture Nutrient Data Laboratory reports that 1 oz. of toasted sunflower seed kernels (no salt) contains 175 calories; 16 g of fat; 5 g of protein; 16 mg of calcium; 2 mg of iron; 37 mg of magnesium; 328 mg of phosphorous; 139 mg of potassium; and 1.5 mg of zinc.
Sunflower seeds are sold raw, roasted, salted or in-shell. Like any salted nut, sunflower seeds with added salt can be high in sodium and are not recommended for people following a low-sodium diet. Roasted sunflower seeds have added oils and can be high in fat. The nutritional benefits of sunflower seeds are duplicated in sunflower oil, sunflower butter and bread products. Sunflower seeds are a common ingredient in trail mix and nut breads.
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