Hello.
Vitamin D3 levels of 12.3 are extremely low. You will have to start taking oral vitamin.
UpriseD3 60k/ Lumia 60k both are equally good products. And either if them have no side effects. Please remember to set your reminder as its a weekly dose and we tend to forget. Please complete the whole course of 8 weeks and continue taking such 8 weeks courses once every 6 months for coming 2-3 years.
You should also consider taking
Calcium tablets every night as Vitamin D3 capsules will absorb more calcium into your bones.
Another step would be to include naturally available
vitamin D sources in your diet like fish,
liver, seeds, nuts, butters and oil.
Sunlight is a good source of Vit D. So every morning, a 10-20 minutes of sunshine ~ 6:30am (may not be possible due to weather currently) is also a good exercise to follow on a long term basis.
Please continue your Cabergoline as it has no reactions with vitamins. If at all, there comes a times, when you are to take both the medicines together, a safe gap of 10-15 minutes between the 2 drugs should be enough.