References:


¹⁰ NHS – Vitamin B12 Deficiency Guide, 2023


¹¹ Moore et al., British Journal of Nutrition, 2012 – B12 and nervous system support


4. Holick MF. (2004). Sunlight and vitamin D for bone health and prevention of autoimmune diseases, cancers, and cardiovascular disease. Am J Clin Nutr, 80(6 Suppl):1678S–1688S


³ Viva! – The Truth About B12 and Vegan Diets


⁵ Allen LH. Causes of vitamin B12 and folate deficiency. Food Nutr Bull. 2008;29(2 Suppl):S20–S34


⁶ Tucker KL et al. Vitamin B12 status and intake among older adults: Framingham Offspring Study. Am J Clin Nutr. 2000;71(2):514–522
7. Holick MF. Vitamin D deficiency. N Engl J Med. 2007;357(3):266–281.
7. Nair R, Maseeh A. Vitamin D: The “sunshine” vitamin. J Pharmacol Pharmacother. 2012;3(2):118–126
8. B vitamins and mood improvement – Kennedy, Nutrients, 2016
9. Vitamin D and immune modulation – Aranow, Journal of Investigative Medicine, 2011
10. B12 and energy metabolism – NHS, Vitamin B12 Deficiency Guide, 2023
11. B12 and nervous system support – Moore et al., British Journal of Nutrition, 2012
12. Vitamin D and neuromuscular function – Ceglia, Current Opinion in Clinical Nutrition, 2009
13. Vitamin D and mood regulation – Cheng et al., Nutrients, 2020
14. Vitamin D and adaptive immunity – Baeke et al., Frontiers in Immunology, 2010
15. B12 and fatigue recovery – Sanz-Cuesta et al., BMJ Case Reports, 2013
16. Vitamin D and inflammation – Berridge, Physiological Reviews, 2017
17. B vitamins and sustained energy/mood – Kennedy, Nutrients, 2016
18. Vitamin D and respiratory infections – Martineau et al., BMJ, 2017
19. Vitamin D and biological aging – Chen et al., Frontiers in Aging, 2021
20. B12 and long-term brain health – O'Leary & Samman, Nutrients, 2010. – O'Leary & Samman, Nutrients, 2010.


²¹ U.S. Environmental Protection Agency. EPA Exposure Factors Handbook


²² Holick MF. (2004). Sunlight and vitamin D for bone health and prevention of autoimmune diseases, cancers, and cardiovascular disease. Am J Clin Nutr, 80(6 Suppl):1678S–88S

²³ Matsuoka LY et al. (1987). Sunscreens suppress cutaneous vitamin D3 synthesis. J Clin Endocrinol Metab, 64(6):1165–1168


²⁴ Clemens TL et al. (1982). Increased skin pigment reduces the capacity of skin to synthesize vitamin D3. Lancet, 319(8263):74–76


²⁵ Holick MF et al. (1989). Vitamin D3 production in human skin decreases with age. J Clin Invest, 76(4):1536–1538


²⁶ National Health Service (NHS). Vitamin D – who needs it, and how to get it. nhs.uk