India: A research paper published in BMC Nephrology has concluded that There is no association between vitamin D deficiency and disease profile and renal outcome in Indian patients with IgAN.
It is already known that a deficiency of Vitamin D is a risk factor associated with the severity and progression of kidney disease. This is because of its immunomodulatory effects.
More research data must be collected about its impact on IgA nephropathy (IgAN).

Considering this background, a study was done by Naba Farooqui and colleagues from the All India Institute of Medical Sciences, New Delhi, India.
Vitamin D level of < 10 ng/mL was defined as Vitamin D deficiency.
The study points include the following:
25 (OH) vitamin D assay was performed with serum samples collected during the kidney biopsy of 105 adult patients.
These patients were diagnosed with primary IgAN between 2015 and 2019.
69.5 % of study participants were males, and the mean age of the patient was 34 ± 10.6 years.
Vitamin D levels were 15.9 ± 11.9 ng/mL at baseline.
Forty-one patients constituting 39 %, had vitamin D deficiency.
Vitamin D deficient patients had a lower serum albumin level than those with a higher level of vitamin D (3.7 ± 0.9 vs 4.1 ± 0.7 g/dl). The differences in baseline proteinuria and eGFR were not significant.
In the Vitamin D deficiency group, Crescentic lesions were more (19.5% vs 6.3%).
There was no difference recorded in remission (68.3% vs 65.6%) and disease progression (12.5% vs 9.4%) )with and without Vitamin D deficiency of follow-up of 21.5 months.
Vitamin D deficiency is not a significant risk factor for renal survival, having HR-1.79.
To conclude, vitamin D deficiency per se may not impact disease outcomes in IgAN patients.
Unnecessary treatment may lead to vitamin D intoxication.
Further reading:
Farooqui, N et al. Association of vitamin D status with disease severity and outcome in Indian patients with IgA nephropathy. BMC Nephrol 24, 15 (2023). https://doi.org/10.1186/s12882-023-03061-0