Vitamin A Beta-Carotene

Positive Claims. This vitamin boost immunity has anti cancer effects and fights skin disorders and prevents ageing of the skin.  It also improves and speeds wound healing.

Negative Claims. High dosage is highly toxic, it may cause birth defects during pregnancy. However beta carotene in natural form has the same benefits as preformed Vitamin A, with almost none of its side effects.

Source.  Fish liver oil, meats and animal products are the richest sources of pre formed Vitamin A. Carrots, sweets potatoes, broccoli, spinach, turnip greens cantaloupe, winter squash

Vitamin B1 Thiamin

Positive Claims. Protects against metabolic imbalances caused by intoxicating beverages. It is also beneficial in the treatment of heart disease and is useful in neurological disorder. It is also said to improve mental ability and IQ.

Negative Claims. On the flip side is the fact that at very high dosages it can prove toxic 

Source.  All plant and animal foods contain thiamin, Good sources are whole grain products, brown rice, sea food and beans. 

Vitamin B2 Riboflavin;

Positive Claims. Riboflavin protects exercisers from antioxidant damage and boosts athletic performance. It also protects against cancer and anaemia.

Negative Claims. It is said to be toxic in high dosages

Source. Good sources include milk cheese, yogurt, green leafy vegetables fruits bread cereals and meats.

Vitamin B3 Niacin  

Positive Claims. It lowers cholesterol and protects against cardiovascular disease. It also detoxifies pollutants and narcotics and is helpful against mental disorders.

Negative Claims. Taken in very high dozes may prove toxic.

Source. Dietary sources of niacin include lean meats, fish and poultry