VITAMIN A

In the years following the discovery of the role of vitamin E in rat fertility, researchers quickly began to realize that vitamin A was even more important to reproduction. In Nutrition and Physical Degeneration, Price described the early work on vitamin A deficiency during pregnancy and the preconception period. In diverse species of laboratory animals, this deficiency produced spontaneous abortion; prolonged labor and death of the mother and her offspring during labor; eye defects including the complete absence of eyes; defects of the snout, dental arches and lips; displacement of internal organs including the kidneys, ovaries and testes; and deafness due to degeneration of the nervous system.¹⁵

We now know that vitamin A is necessary for the differentiation and patterning of all of the cells, tissues, and organs within the developing body. It is especially important for the development of the communication systems between the sense organs and the brain.^16,17 Even mild vitamin A deficiency compromises the number of functional units called nephrons in the kidneys, which could predispose a person to poor kidney function later in life.¹⁸ Vitamin A is also necessary during fetal development and through adult life to maintain the presence of cells lining the lungs that are covered in hair-like projections called cilia.¹⁹ These hairs sweep away debris and foreign material, protecting the lungs from pollutants and infectious diseases. During and after the formation of all these systems, vitamin A is necessary for their continued growth.

The RDA of vitamin A for pregnant women is 2,600 IU—just 300 IU more than the RDA for women who are not pregnant. There are several problems with this figure, described in the sidebar below. We do not have exact figures for the vitamin A content of the preconception and pregnancy diets used by the groups that Price studied, but they were certainly higher than 2,600 IU per day. These groups prized organ meats, especially liver, and used them on a regular basis. Preconception and pregnancy diets added additional foods rich in fat-soluble vitamins.

The Weston A. Price Foundation recommends 20,000 IU per day from cod liver oil and additional vitamin A from milk, butter, eggs, and three to eight ounces of liver per week. Yet the medical profession warns pregnant women that this quantity of vitamin A increases the risk of birth defects. This belief can be traced to a single study published in 1995 that purportedly found an increase in the risk of birth defects among mothers consuming more than 10,000 IU per day. As discussed in the sidebar below, there are several important flaws in this study. Every other published study on this subject shows this amount of vitamin A to be safe—indeed, one major study of over 25,000 births showed that daily doses of vitamin A up to 40,000 IU cut the risk of birth defects in half.

Considering the ubiquitous role of vitamin A in the development of every organ system of the body and how tightly the body regulates the level of the activated form, we should expect a generous helping of vitamin A-rich organs and animal fats to help perfect fetal development, not to throw it off course. The preponderance of the evidence suggests that this is the case.