Cataracts and Vitamin D - many studies

Cataracks 50% more likely if Vitamin D Deficient - 2026 233,000 people

Vitamin D Deficiency and Up to 10-Year Risk of Incident Cataract in Adults Aged ≥50: A Propensity Score-Matched Cohort Study

Clin Nutr ESPEN. 2026 Oct 24:105209. doi: 10.1016/j.clnesp.2026.105209 PDF behind paywall

Kuo-Chuan Hung 1, Ting-Sian Yu 2, Ping-Hsin Liu 2, I-Wen Chen 3

Background & aims: Age-related cataracts are a leading cause of blindness, and their prevalence increases markedly after age 50. Vitamin D may help maintain lens homeostasis, but evidence linking vitamin D deficiency (VDD) to cataract risk remains limited. We examined the association between VDD and incident age-related cataract during a follow-up of up to 10 years.

Methods: This retrospective cohort study used the TriNetX Global Collaborative Network. Patients with persistent VDD (two serum 25-hydroxyvitamin D levels ≤19.90 ng/mL) were 1:1 propensity score-matched with those with sufficient levels (≥30.00 ng/mL), with a two-year landmark period. The primary outcome was incident age-related cataract. The secondary outcomes included cataract surgery and all-cause mortality. Positive and negative control outcomes were assessed as complementary evaluations of potential bias.

Results: Each matched cohort included 233,425 patients. VDD was associated with a higher risk of incident age-related cataracts (HR 1.71, 95% CI 1.65-1.78; p<0.001). Cataract surgery (HR 1.78, 95% CI 1.67-1.90; p<0.001) and all-cause mortality (HR 1.48, 95% CI 1.45-1.52; p<0.001) were also more frequent in the VDD group.

The positive control (osteoporotic fracture, HR 1.66, 95% CI 1.51-1.83) supported exposure validity, whereas the negative control (diseases of the appendix) showed no significant association (HR 1.06, 95% CI 0.97-1.16; p=0.180). After additional adjustment for pre-index ophthalmological service utilization, the association remained (adjusted HR 1.66, 95% CI 1.62-1.70).

In an exploratory analysis, vitamin D insufficiency was also associated with incident cataract (HR 1.56, 95% CI 1.51-1.62). Sensitivity analyses showed attenuated but persistent associations when restricting the study period to 2016-2023 (HR 1.46, 95% CI 1.39-1.53) and to patients with documented pre-index ophthalmological service utilization (HR 1.39, 95% CI 1.27-1.52).

Conclusion: VDD was associated with an increased up to 10-year risk of incident age-related cataracts in adults aged ≥50 years. Prospective studies are needed to confirm these findings.

Cataracts associated with 4 ng/mL lower Vitamin D - meta-analysis Aug 2024

Association between vitamin D level and cataract: A systematic review and meta-analysis

Graefe's Archive for Clinical and Experimental Ophthalmology

Zhenzhen Jue, Ziming Xu, Vincent L. Yuen, Odessa Dik San Chan & Jason C. Yam

Purpose

The association between serum vitamin D level and cataract remains controversial. This study aims to evaluate the association between vitamin D level and cataract.

Methods

In this study, articles in the PubMed, Web of Science, and EMBASE databases were searched up to 30 August 2023 and 626 articles were screened. Four studies involving a total of 10,928 subjects with cataract and 10,117 control subjects met the inclusion criteria.

Results

Decreased serum vitamin D level was associated with higher incidence of cataract (P = 0.047; MD: -4.87; 95%CI: [-9.67, -0.07]). In the subgroup analysis by sex, a significant association was found between serum vitamin D level and cataract in both male (P = 0.01, MD: -2.15,95%CI: [-3.83, -0.46]) and female (P < 0.01; MD: -6.67,95%CI: [-8.20, -5.14]).

In the subgroup analysis by the types of cataract, significant association was found between serum vitamin D level and nuclear (P < 0.01; MD: -10.48; 95%CI: [-12.72, -8.24]) and posterior subcapsular cataract (P = 0.02; MD: -6.05; 95%CI: [-11.30, -0.80]) but not in cortical cataract (P = 0.14; MD: -6.74; 95%CI: [-15.70, 2.22]).

Conclusion

This meta-analysis revealed potential association between serum vitamin D level and cataract, more significant in female, and the subtypes of nuclear and posterior subcapsular cataract.

Download the PDF from VitaminDWiki

60K monthly of vitamin D was not enough to reduce the risk of cataracts - clipped from PDF

In a recent randomized controlled trial, participants were randomly assigned to receive regular high-dose

vitamin D supplement (60,000 IU once per month) or placebo, and were followed up for a median duration of approximately 5 years.

The results showed no signifcant diference in cataract surgery rates between the experimental group and the placebo group https://doi.org/10.1016/j.ophtha.2022.09.015. We found that high-level serum Vitamin D reduced the risk of cataract , indicating a potential role of vitamin D supplementation in ophthalmologic practice. (behind paywall)

Glutathione (master antioxidant) should reduce the risk of cataracts (Perplexity AI Oct 2024)

Glutathione appears to play an important role in reducing the risk of cataracts:

Glutathione's Protective Effects

Glutathione is a powerful antioxidant that helps protect the lens of the eye from oxidative damage, which is a major contributor to cataract formation   1 3

Some key points about glutathione and cataracts:

  • Glutathione levels are significantly lower in lenses with cataracts compared to healthy lenses

1

  • It is considered one of the most important antioxidants for ocular health, reacting directly with oxidants and free radicals  2

  • Glutathione helps reduce oxidative stress in the lens, which is a key factor in cataract development  3

    Mechanisms of Action

Glutathione protects the lens through several mechanisms:

  • It detoxifies oxidants and free radicals that can damage lens proteins  1

  • It works synergistically with vitamin C to promote eye health  2

  • Glutathione improves the antioxidant capacity of ascorbate (vitamin C) in the lens  3

    Challenges with Supplementation

While glutathione shows promise for cataract prevention, there are some challenges with direct supplementation:

  • It's unclear if glutathione eye drops can effectively penetrate the cornea to reach the lens

2

  • Oral glutathione supplements may have limited bioavailability  4

    Alternative Approaches

Some alternative strategies to boost glutathione levels and protect against cataracts include:

  • Using precursors like N-acetylcysteine (NAC) or N-acetylcysteine amide (NACA) to boost glutathione production  4  5

  • Activating the NRF2 pathway, which regulates glutathione synthesis, through compounds like sulforaphane  4

  • Ensuring adequate intake of other antioxidants like vitamin C and E, which work alongside glutathione   2  3

While more research is needed, maintaining healthy glutathione levels appears to be an important factor in reducing cataract risk. A diet rich in antioxidants and potentially targeted supplementation may help support lens health and glutathione function.

VitaminDWiki - Glutathione and Vitamin D synergism - many studies

*Liposomal form is very bioavailable *