During a visit to London in 1931, Mahatma Gandhi—who had joined the Vegetarian Society's executive committee when he lived in London from 1888 to 1891—gave a speech to the society arguing that it ought to promote a meat-free diet as a matter of ethics, not health. This lent support to the vegan position, although Gandhi himself drank goat's milk. During a visit to London in 1931, Mahatma Gandhi—who had joined the Vegetarian Society's executive committee when he lived in London from 1888 to 1891—gave a speech to the society arguing that it ought to promote a meat-free diet as a matter of ethics, no
In addition, many hives are culled post-harvest to keep farmer costs down. Queen bees often have their wings clipped by beekeepers to prevent them leaving the hive to produce a new colony elsewhere, which would decrease productivity and lessen profit. A 2010 UN report, Assessing the Environmental Impacts of Consumption and Production, argued that animal products "in general require more resources and cause higher emissions than plant-based alternatives".:80 It proposed a move away from animal products to reduce environmental damage. A 2007 Cornell University study concluded that vegetarian diets use the least land per capita, Vitamin D comes in two forms. Cholecalciferol (vitamin D3) is synthesized in the skin after exposure to the sun, or consumed in the form of animal products; when produced industrially it is taken from lanolin in sheep's wool. Ergocalciferol (vitamin D2) is derived from ergosterol from UV-exposed mushrooms or yeast and is suitable for vegans. Conflicting studies have suggested that the two forms may or may not be bioequiva.