# References

[https://www.ncbi.nlm.nih.gov/books/NBK114302/#ch9.s60](https://www.ncbi.nlm.nih.gov/books/NBK114302/#ch9.s60)

[https://ods.od.nih.gov/factsheets/VitaminB12-HealthProfessional/](https://ods.od.nih.gov/factsheets/VitaminB12-HealthProfessional/)

[https://ods.od.nih.gov/factsheets/Calcium-HealthProfessional/](https://ods.od.nih.gov/factsheets/Calcium-HealthProfessional/)