To circumvent the US embargo against Cuba and lagging domestic production, milk has to come from the other side of the world in an obstacle race that deprives many on the island of the staple. Regla Caridad Zayas, a 59-year-old diabetic, said the milk powder that the Cuban state supplies monthly to her and others with special dietary needs dried up months ago. She is supposed to get a kilo of powder, which makes 10 liters (2.6 gallons) of milk, every month. Sitting at a rickety table from which she sells coffee outside her house, Zayas said the bodegas, or subsidized food stores, no longer car…