Publications and Resources. Read the groundbreaking 1977 publication â Phylogenetic structure of the prokaryotic domain: The primary kingdoms ,â by Carl R. Woese and George E. Fox, in which Archaea, the third domain of life, is identified.
Youâre quite right that cod liver oil is a good source of vitamin D. According to the National Institutes of Health, it gives you 1,360 IU per tablespoon (I now recommend 2,000 IU daily). However, at least some kinds of cod liver oil provide as much as 13,500 IU of vitamin A, and thatâs way too much. The Upper Limit of vitamin A set by the Food and Nutrition Board of the National Academy of Sciences is 10,000 IU per day.
My understanding is that different brands of cod liver oil vary greatly in total vitamin A content. Carlson cod liver oil contains approximately 800 IU of vitamin A per teaspoon. Physicians and scientists aren't in agreement on what a safe upper level of vitamin A is for the average adult.Some feel that up to 10,000 IU per day is safe.arlson cod liver oil contains approximately 800 IU of vitamin A per teaspoon. Physicians and scientists aren't in agreement on what a safe upper level of vitamin A is for the average adult.