Sources:

[1] [2] [3] [4] [6] [14] [25] [26] [31] [32] [33] [50] Vitamin D Deficiency - StatPearls - NCBI Bookshelf https://www.ncbi.nlm.nih.gov/books/NBK532266/

[5] Preventing Falls and Hip Fractures | Older Adult Fall Prevention | CDC https://www.cdc.gov/falls/prevention/index.html

[7] [8] [9] [10] [12] [13] [17] [18] [19] [20] [22] [23] [27] [29] [36] [42] [43] [45] [46] [47] [49] Vitamin D • The Nutrition Source https://nutritionsource.hsph.harvard.edu/vitamin-d/

[11] Vitamin D supplementation to prevent acute respiratory tract infections https://www.bmj.com/content/356/bmj.i6583

[15] [16] The effect of vitamin D supplementation on depression: a systematic review and dose–response meta-analysis of randomized controlled trials | Psychological Medicine | Cambridge Core https://www.cambridge.org/core/journals/psychological-medicine/article/effect-of-vitamin-d-supplementation-on-depression-a-systematic-review-and-doseresponse-metaanalysis-of-randomized-controlled-trials/8F18452740B621CC04F441F037A2513B

[21] [24] [28] [30] [34] [35] [40] Vitamin D and Skin Health | Linus Pauling Institute | Oregon State University https://lpi.oregonstate.edu/mic/health-disease/skin-health/vitamin-D

[37] UV radiation and the skin - PubMed https://pubmed.ncbi.nlm.nih.gov/23749111/

[38] [39] [41] [44] Your Vitamin D Dilemma, Solved: Don’t Get it From the Sun | Hartford Hospital | Hartford, CT https://hartfordhospital.org/about-hh/news-center/news-detail?articleid=43107&publicId=395

[48] Deaths from Fall-Related Traumatic Brain Injury — United States, 2008–2017 | MMWR https://www.cdc.gov/mmwr/volumes/69/wr/mm6909a2.htm