Funding for this research was provided by:
Received: 21 June 2017
Accepted: 3 January 2018
First Online: 24 January 2018
Ethics approval and consent to participate
: All relevant registries are accessible and the collection of data from these registries is in accordance with accepted ethical principles for informed consent and according to the Declaration of Helsinki. The access and linkage permission from the Danish Data Protection Agency to provide access to the Danish Civil Registration System has been granted (J. no.: 2010–41-4485). This permission includes merging civil registration numbers with the different registers. Statistics Denmark will create the relevant sub-datasets, but before access is allowed the civil registration numbers are anonymized.Permission to access and analyze the DBS samples for fatty acids has been granted from the Ethical Committee of the Capital Region of Denmark (Protocol no.: H-16015825).
: Not applicable.
: The authors declare that they have no competing interests.
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