At high dosages B vitamins cause side effects such as nausea, diarrhea, various gastrointestinal symptoms, and vomiting. High dosages of vitamin B may also cause restlessness and insomnia. High doses of vitamin B 6 causes the side effect of peripheral neuropathy. Symptoms of vitamin B 6 toxicity include pain and numbness of the extremities, and in severe cases difficulty walking.

How much vitamin B is necessary? Most of the B-complex in the stores are 50 and 100 mg tablets. The RDA or daily value for most of the common B vitamins such as B1, B2, and B6 is about 2 mg, yet many supplements on the market have 50 to 100 mg of vitamin B, which equates to 10 to 50 times the RDA. We really don't think we need that much. As a general rule, taking a dosage of vitamin B between 2 to 10 mg a day should be fine for most people.

The RDA for calcium for people 14-18 years old is 1,300 mg/day.

The RDA of folates for women 19 years old or women of childbearing age is 300mcg/ 10 lb/day. I will round your weight off to 100 pounds; so you would need 10x300mcg/day or 3,000 mcg/day.

There is no established RDA for omega-3 fatty acids but one site recommends 1,500- 3,000 mg per day depending on diet, weight and genetics.