Changes in 25‐hydroxyvitamin D levels post‐vitamin D supplementation in people of Black and Asian ethnicities and its implications during COVID‐19 pandemic: A systematic review

Abstract

Background People of Black and Asian ethnicities have a higher infection rate and mortality as a result of COVID‐19. It has also been reported that vitamin D deficiency may play a role in this, possibly because of the multi‐gene regulatory function of the vitamin D receptor. As a result, increased dietary intake and/or supplementation to attain adequate 25‐hydroxyvitamin D (25(OH)D) levels could benefit people in these ethnicities. The present study aimed to review the literature examining the changes in 25(OH)D in different types of vitamin D supplementation from randomised controlled trials in this population. Methods This systematic review was conducted using the PRISMA guidelines. Electronic databases were systematically searched using keywords related to vitamin D supplementation in Black and Asian ethnicities. Results Eight studies were included in the review. All the included studies found that supplementation of vitamin D (D 2 and D 3 ), regardless of dosage, increased 25(OH)D levels compared to a placebo. All trials in which participants were vitamin D deficient at baseline showed increased 25(OH)D levels to a level considered adequate. Two studies that used food fortification yielded smaller 25(OH)D increases compared to similar studies that used oral supplementation (10.2 vs. 25.5 nmol L −1 , respectively). Furthermore, vitamin D 2 supplementation yielded significantly lower 25(OH)D increases than vitamin D 3 supplementation. Conclusions Oral vitamin D supplementation may be more efficacious in increasing 25(OH)D levels than food fortification of Black and Asian ethnicities, with vitamin D 3 supplementation possibly being more efficacious than vitamin D 2 . It is recommended that people with darker skin supplement their diet with vitamin D 3 through oral tablet modes where possible, with recent literature suggesting a daily intake of 7000–10,000 IU to be potentially protective from unfavourable COVID‐19 outcomes. As a result of the paucity of studies, these findings should be treated as exploratory.

Does vitamin D supplementation reduce COVID-19 severity?: a systematic review

“…The lowest dose administered was 400 IU while 60 000 IU was the highest. 23 Another study by Nikniaz et al . 17 supplemented the intervention group with oral vitamin D3 (60 000 IU–80 000IU).…”

“…Most of the studies considered for this evidence summary have used vitamin D supplementation in oral form either as oral cholecalciferol or oral calcifediol. 15 , 17–19 , 23 The dosage of the supplementation varied in the studies. Booster therapies given were in the range of 280 000 IU or 400 000 IU.…”

The Interaction of Vitamin D and Corticosteroids: A Mortality Analysis of 26,508 Veterans Who Tested Positive for SARS-CoV-2

“…Vitamin D (Vit D) is an oxysterol hormone with important immunomodulatory and antiviral properties [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 ]. Even though this vitamin is often recommended as a nutritional supplement in treatment guidelines and prescribed for the management of coronavirus disease 2019 (COVID-19) [ 9 , 10 , 11 , 12 ], several studies have yielded divergent or inconclusive results [ 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 ].…”

Food nutrients as inherent sources of immunomodulation during COVID-19 pandemic

“…In addition, a negative association between serum 25(OH)D levels (a marker for Vitamin D insufficiency) and COVID-19 severity was reported in some studies. This promotes to add vitamin D in the diet through dietary intake via food fortification as a potential protective measure against the infection and mortality ( Vaughan et al, 2021 ). The encapsulation of vitamin D is a most suitable method of fortification because it protects from degradation before reaching to target site in body.…”