As a retired doctor of traditional Asian medicine who specialized in reproductive endocrinology for 20 years using nutrition, acupuncture and herbs to correct autoimmune and other reproductive issues, I take James Corcoran, a vegan, to task for his misleading My View (“Meat-eating plays very small role in good health,” April 8).

First and foremost, I have found vegans to be staunch in their belief system without backup science. Nor has there ever been a culture of people exclusive to a vegan diet because this diet does not support the endocrine system, which includes reproduction. If a culture of people cannot reproduce, the diet has to be seriously reconsidered. There are cultures that are supported by a vegetarian diet because it includes animal products like dairy, and eggs and bone broth soups, etc. Even so, many contemporary vegetarians consume more processed carbs than what these vegetarian cultures would have eaten traditionally, i.e. before processed foods.

The danger of vegetarian and especially vegan diets is nutrient deficiencies. Certain vital nutrients occur only in animal foods, which are particularly important for fetal development and growing children.

Here is what a vegan diet often lacks and animal products provide for optimal health in humans:

• Eicosapentaenoic acid and docosahexaenoic acid are critical for brain function. Best sources are cod liver oil, organ meats and seafood.

• Arachadonic acid is critical for healthy cell-to-cell junctures in the skin and intestinal tract and for life-saving inflammation response. Best sources are animal fats and organ meats.

• Amino acids are critical for many functions in the body, including energy and brain function. Best sources are meat, seafood and organ meats.

• Iron is needed for red blood cells, energy and immunity, and best assimilated from liver and red meat. One can get some iron from green-plant sources.

• Calcium is found in plants but dairy foods are the best source of usable calcium.

• Zinc is required for cell replication, skin integrity, immunity, digestion, glucose tolerance, high metabolic rate and sense of taste. Best sources are red meat and shellfish.

• Vitamin B6 is involved in brain function. We use the plant form of B6 much less effectively than the animal form. Best sources are muscle meats, seafood, organ meats and raw milk.

• Vitamin A is found in cod liver oil, liver, butter and egg yolks from grass-fed animals.

• Vitamin D is essential for growth and bones. It shields against heart disease, obesity and arthritis. Vitamin D is necessary for the “feel-good chemicals” in the brain. Best sources are cod liver oil, lard, pork, shrimp, oily fish and egg yolks from grass-fed poultry.

• Vitamin K2 is required for the synthesis of brain cells and reproduction, and critical for ensuring that calcium is put into the hard tissues (bones and teeth). Best sources in the Western diet are poultry liver and aged, full-fat cheese.

• Vitamin B12 is not found in plant foods and is needed for red blood cell production. All animal foods provide B12, but liver is the best source.

Infertility in this country is becoming a part of the “degenerative” diseases that plague our population. I had a 65 percent success rate with couples becoming pregnant just by altering their diet and lifestyle. Some were vegetarians; none were vegans.

Claudia B. Wolfe is a retired doctor of traditional Asian medicine who lives in Santa Fe.