safe to these vitamin at same time?!

Yes, it fine to take these supplements together.

There are scientific evidence that Ginkgo biloba would be helpful with memory. Not all results are positive, however. It may not be very effective for improving memory in people who don't have memory problems. Dosage used ranges from 80 mg twice daily to 200 mg three times daily.

http://www.natural-remedies-review.com/g…

Human studies suggest lecithin might improve memory. Some health experts say we get enough lecithin from our diets, so we don’t need to take a lecithin supplement. Others believe that because many people don’t eat enough high lecithin foods, supplementing the diet with lecithin can benefit us. A tablespoon of lecithin granules or powder to our cereal each day is a cheap and easy way to add more lecithin to the diet.

http://extrahappiness.com/happiness/?p=1…

Research shows B vitamins improve memory by creating a protective shield for the neurons in the brain. B vitamins break down homocysteine - an amino acid that is a toxic poison to nerve cells. B vitamins also aid in the production of red blood cells, which carry oxygen, an important brain nutrient. The most important B vitamins for memory include B6, Folic Acid (B9) and B12. The symptoms of vitamin B12 deficiency are practically indistinguishable from Alzheimer's disease and senile dementia. The B vitamins all work synergistically so a B complex is a good choice. There is a sublingual spray called homocysteine spray with B6, B9 and B12 to lower toxic homocysteine levels.

http://www.health4youonline.com/health_s…
http://www.buzzle.com/articles/b-complex…
http://vitamins.lovetoknow.com/Signs_of_…

Antioxidants are also important for memory. Antioxidants protect brain tissue by breaking down free radicals, which are toxic forms of the oxygen molecule natually found in the bloodstream. Free radical damage can impare the functioning of the neurons in your brain. Powerful antioxidants include A, C, E and selenium. Antioxidants daily to help with free radical damage - 1000 mg of vitamin C, 400 IU of vitamin E, 200 mcg of selenium. The safest way to give Vitamin A is as beta-carotene, as the body will convert it into vitamin A as needed and overdose is automatically avoided. 15 to 50 mg (25,000 to 83,000 IU) beta carotene per day is recommended.

http://www.vitamins-supplements.org/beta…
http://healthpsych.psy.vanderbilt.edu/Vi…
http://www.memory-improvement-tips.com/v…

Omega-3 fatty acids are important fat molecules that enhance memory and brain function. These fats help protect the brain against inflammation. In order to obtain optimal health benefits, recommended doses start at 1,200 mg of EPA plus DHA per day, usually provided by taking 4,000 mg of total fish oil per day, as most fish oil supplements contain 180 mg EPA and 120 mg DHA (300 mg per capsule).

http://www.livestrong.com/article/15379-…

RedAngel

Vitamin supplements are best avoided. In the UK at least deficiencies are rare and there is neither need nor therapeutic advantage in taking supplements. Recently there has been increasing concerns about what is effectively overdosing on synthetic vitamins. The fat soluble vitamins are the most potentially toxic, A to the eye, D to the kidney K to the blood clotting mechanism and E appears to increase all cause mortality. The most recent, and one of the most worrying papers concerns women taking multivitamins. There appears to be an associated 19% increase in the risk of breast cancer in women on multivitamin tablets, though further investigation is required to confirm that the risk is causal.

GP for more years than I care to remember

I take multi vitamin/mineral tablet, odorless garlic and cod-liver oil everyday and I'm in good health lol. Just don't overload the RDA of each. As for improving memory? More use of it may help, I doubt you'll find a miracle cure though.