Vitamins

Any vitamins and nutritional supplements

World Health Store
The World Health Store has a big selection of vitamins and other health products. Lots of locations, including:

Shanghai Centre (Portman Centre/Ritz Carlton): 1376 Nanjing Xi Lu, between Jingan Temple and Nanjing Xi Lu metro stations, line 2

Kerry Parkside, Pudong: Huamu Lu metro, line 2, Basement level

Jingan Kerry Centre: 1563 Nanjing Xi Lu B2 level, Jingan Temple metro, line 2

Watsons
You can buy multivitamins like Centrum at most Watsons.

Local pharmacies
Most pharmacies have brands like Centrum, Redoxon and Materna.