Marine-D3, which contains a 2,000 IU dose of vitamin D3 in two capsules, generally has few side effects, states ConsumerLab.com. If a person takes too much Marine-D3 or another supplement with vitamin D3, it results in dangerously high calcium levels that cause vomiting, nausea, thirst, tiredness and constipation, notes WebMD.
The daily recommended dose of vitamin D3 in an average adult is 400 IU, states ConsumerLab.com. The dose found in Marine-D3 can be beneficial to a person who does not get enough of the vitamin, although there are more cost-effective ways to get it, such as stepping outside in the sun, states Everyday Health. Marine-D3 also contains omega-3 fatty acids from calamari oil, but there are again more efficient ways to get this than the supplement, such as consuming fish twice a week.
People who take phosphate binders must not take Marine-D3 because of possible interactions, states WebMD. Also, those taking medications with calcitriol must not take Marine-D3, because calcitriol is very similar to vitamin D. Vitamin D3 can also interfere with cholesterol tests and yield false results.
Another ingredient in Marine-D3 is brown seaweed, but there is not enough medical evidence that lists its potential side effects, states ConsumerLab.com. While Marine-D3 claims to be an anti-aging product, there is not enough medical research to back it up.