One of the 13 vitamins your body needs for optimum function, vitamin B-6 plays a role in immune function, nerve health and metabolism. Because vitamin B-6 is water soluble, your body excretes any excess, rather that storing it for later use. For this reason, a regular supply of vitamin B-6 from your diet is vital. However, although your body gets rid of any extra B-6, high dosages can be toxic.
Recommendations
It only takes a relatively small amount of B-6 to meet your body's demand for the vitamin. For adults up to age 50, the recommended dietary allowance for vitamin B-6 is 1.3 mg. A 50 mg B-6 supplement, then, provides 38 times the recommended amount for this age group. After age 50, men need 1.7 mg and women need 1.5 mg. Pregnant and lactating women need 1.9 mg and 2 mg, respectively. To put this in perspective, 1 cup of spinach provides .44 mg of vitamin B-6, a banana provides .43 mg and 3 oz. of wild salmon provides .48 mg.
Toxicity
Too much vitamin B-6 in supplement form can lead to sensory neuropathy, signified by pain and numbness in the fingers and toes, according to the Linus Pauling Institute. Difficulty walking can be a sign of severe vitamin B-6 toxicity. However, toxicity is associated with vitamin B-6 intakes of more than 1,000 mg daily, or extended consumption of 500 mg daily. Although 50 mg is much more than the recommended intake of vitamin B-6, this amount is not typically associated with serious side effects.
Dosages
The Institute of Medicine set the upper tolerable intake for vitamin B-6 at 100 mg daily. This is the highest level with which adverse side effects are unlikely. The typical dosage for treating vitamin B-6 deficiency is 2.5 mg to 25 mg daily for three weeks, followed by a lesser dosage during the maintenance phase of 1.5 to 2.5 mg daily, according to MedlinePlus.
Considerations
Your doctor is the best resource for determining whether you need vitamin B-6 supplements, as well as which dosage is right for you. In some cases, your doctor may prescribe temporary B-6 dosages higher than the upper tolerable intake to help treat conditions such as anemia. Most healthy people can get adequate amounts of vitamin B-6 in their diets from food sources such as salmon, turkey, chicken, potatoes, spinach and fortified cereal.
References
- MedlinePlus: Vitamins
- MedlinePlus: Vitamin B-6
- Institute of Medicine: Dietary Reference Intakes (DRIs): Recommended Dietary Allowances and Adequate Intakes, Vitamins
- Linus Pauling Institute at Oregon State University: Vitamin B-6
- Institute of Medicine: Dietary Reference Intakes (DRIs): Tolerable Upper Intake Levels, Vitamins
- MedlinePlus: Pyridoxine (Vitamin B-6)
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