While there is not an official "Pause" or "Hold" option, you can "Skip" orders, and change your shipping dates as you see fit for each product. You can push your next order date as far back as you would like, even 6 months or more, for example.
Once you log into your account, select "Manage Subscriptions." You'll then want to click "Next Box Ships On" to change your ship dates and select the preferred date from the calendar pop-up. After clicking "Update", your changes will be saved. If you wish to skip a shipment for any product, simply click on the "Skip" button underneath each product to make the change.
You can also click on the arrow next to each product itself, and it gives you the option to change your Frequency, and Next Shipment Date.