How do Seventh Day Adventists interpret Romans 14:5? In the same way, some think one day is more holy than another day,
  while others think every day is alike. You should each be fully
  convinced that whichever day you choose is acceptable.
  ‭Romans‬ ‭14‬:‭5‬ NLT


How do Seventh Day Adventists interpret this verse?
Seventh Day Adventists do not view Romans‬ ‭14‬:‭5‬ to be about the 4th commandment. We do not believe that the ten commandments (God's moral laws) were abolished at the cross. The law of love would cause Christians to want to keep God's moral laws through grace (i.e. not murder, not commit adultery), it does not free them to then freely murder. The same logic is applied to the 4th commandment, which is specified as the 7th day of the week in the commandment (Exodus 20:10).

Therefore, when Romans 14:5 is read in this context, we believe it is referring to religious holidays. The central issue during the apostolic times were circumcision, eating foods sacrificed to idols, keeping ceremonial feasts and holy days (including the rest days of those festivals). We are free to not keep ceremonial feasts and holy days because they were a "shadow of things to come" (Colossians 2:16-17) (i.e. they were ceremonies that pointed forward to the actual works of Jesus). However, the Sabbath is not a shadow, it represents a memorial of creation, sanctified at creation by God Himself.

Based on the comments on this page, here are a few other points of clarification:


The vegetarians in Roman 14:1 is about those early Christians who became vegetarians to avoid food sacrificed to idols, in accordance to Act 15:29. However, the vegan diet advocated by 7th Day Adventists relates to modern foods. Modern animals are raised entirely different from how they used to before. This is the same reason why the organic food movement is popular today, except 7th Day Adventists realized this in the 1850s. Vegetarianism is not a requirement but is greatly advised for heath reasons.
While Sabbath keeping Adventists do believe that breaking the Sabbath is a sin, they do believe all those who kept Sunday prior to God revealing this light to them are accepted. Those who are introduced to this topic, however, must search diligently and sincerely for the truth in the Bible until they are fully convicted (one way or the other). Sunday worship is not the mark of the beast today, but will be when it eventually becomes mandatory by law in the future, restricting religious liberty. Then it will become a great test on which men decide to serve God or the traditions of men.


For additional study of Roman 14:5, here is a short 2 min video from amazingfacts.org, scroll down to bottom for the transcript.

http://www.amazingfacts.org/media-library/media/e/1294/t/does-romans-145-refer-to-the-weekly-sabbath.aspx