. Author manuscript; available in PMC: 2019 Jun 1.

Published in final edited form as: Br J Haematol. 2018 May 16;181(6):828–835. doi: 10.1111/bjh.15270

Table III.

Quarterly Variations in 25-OHD Levels in SCD Patients.

Quarter	1	2	3	4
Month	Nov–Jan	Feb–Apr	May–July	Aug–Oct
N	79	55	52	82
25-OHD (ng/ml)	10 (7–20.5)	12 (8.3–27.5)	12.5 (8.5–20)	15 (9–23)
Pairwise comparison vs. Quarter 1	NA	0.105	0.197	0.016
Pairwise comparison vs. Quarter 2	0.105	NA	0.778	0.586
Pairwise comparison vs. Quarter 3	0.197	0.778	NA	0.399

Quarters are based on the duration of daylight: 1. November to January; 2. February to April; 3. May to July; 4. August to October. Patients taking vitamin D supplementation when 25-OHD levels were measured were excluded from this analysis. The 25-OHD levels were compared using the Kruskal–Wallis test and the Conover-Inman Test for All Pairwise Comparisons.