No link between vitamin D and AMD

New research has cast doubt over a connection between vitamin D deficiency and age-related macular degeneration.

A new study, published in Ophthalmology, suggests there is no causal link between vitamin D deficiency and age-related macular degeneration (AMD).

The study involved 4753 participants from different locations with a diverse range of diets and levels of sunlight exposure. The average age of the participants who provided a blood sample was 73.

Among the cohort, 2137 participants had no signs of the degenerative condition, 2209 had early AMD, while 150 patients had a late-stage diagnosis. Of this last group, 104 participants had neovascular AMD.

Dr Astrid Fletcher, from the London School of Hygiene and Tropical Medicine, explained to OT that the study found no association between vitamin D intake and AMD.

A previous study, in the United States found a connection between vitamin D deficiency and AMD.

Dr Fletcher outlined how her research team aimed to investigate the relationship between vitamin D and early and late AMD using both blood measures of vitamin D, and genetic variants that are known to influence vitamin D concentrations.

“These variants come from seven genes which play an important role in vitamin D uptake, transport and metabolism,” she explained.

“If there was an association with vitamin D genetic variants and AMD this would provide stronger evidence for a causal association of vitamin D and AMD,” Dr Fletcher added.

The study found no association between vitamin D and early AMD. There was a small increased risk of neovascular AMD in people with vitamin D deficiency, but the research found that it was unlikely that the association was causal, Dr Fletcher highlighted.

“Our results do not support a role of vitamin D in AMD,” she emphasised.

“Clearly older people should consult their GPs for advice regarding vitamin D, but the reason for that is because of the well-known risks of vitamin D deficiency on bone health and not because of any impact on AMD,” Dr Fletcher added.

Because there were few studies in the field, the research team’s findings would need to be corroborated in other settings using other study designs, especially longitudinal studies, she explained.

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