Low levels of vitamin D could also be related to an enhanced risk of diabetic retinopathy, in keeping with a brand new study. It’s just the most recent in a history of labor to discover a connection between the 2 conditions, though the potential mechanism linking the 2 stays mysterious.
The latest study, published in Clinical Nutrition ESPEN, analyzed the information from 402 adults with type 2 diabetes, half of whom had diabetic retinopathy (DR). The 2 groups were very similar in most ways: There was no real difference in average age, weight, A1C, cholesterol, or use of diabetic medications. The researchers found three differences common to those that had developed diabetic retinopathy:
- Higher systolic blood pressure (142 mmHg vs. 130 mmHg). Blood pressure is thought to be considered one of the main causes of diabetic retinopathy, in concert with high blood sugar.
- Longer duration of diabetes (8.5 years vs. 6.0 years). Duration of diabetes is one other known risk factor for diabetic retinopathy and other complications; the longer the body endures diabetes, the more time high blood sugar levels should cause damage and dysfunction.
- Higher likelihood of vitamin D deficiency. 58.9 percent of those with DR had vitamin D deficiency, compared with only 33.3 percent of those without DR. Those with DR were also lower than half as more likely to have normal vitamin D status.
Dozens of comparable studies have found similar connections. In a big 2022 review, researchers considered 36 studies to have investigated the link between DR and vitamin D, and located that 30 of them identified a correlation between low vitamin D levels and the complication — including studies of individuals with each type 1 and sort 2 diabetes. Only a handful of the 36 studies reported no association in any respect.
Nevertheless, in a statement to the American Academy of Ophthalmology’s EyeNet Magazine, a spokesman from the team of researchers said that they were reluctant to attract conclusions because the research has been hampered by small sample sizes and a scarcity of standardized protocols. Larger and more robust experiments are still needed.
How might it work? The mechanism by which low vitamin D levels could hasten retinopathy remains to be a matter of conjecture. A 2023 review outlines a number of the possibilities. Amongst other theories: Vitamin D has anti-inflammatory properties, which could help quell an overactive immune system within the eyes, and the nutrient may help prevent the formation of abnormal latest blood vessels that scar the retina in late vision-threatening DR.
As yet, though, that is all conjecture. Vitamin D deficiency is just not listed as a reason behind DR in an American Academy of Ophthalmology article on the topic. And there may be also a possibility that the causation moves in the other way: Perhaps individuals with diabetic retinopathy are less more likely to spend time outside within the sun, and that’s the reason behind their lower vitamin D levels?
Vitamin D and Diabetes
The broader connections between vitamin D and diabetes have been a spotlight of intense research for a few years. Individuals with type 1 and sort 2 diabetes generally have lower levels of vitamin D than most of the people, and vitamin D deficiency has been investigated as a possible contributing factor for each conditions.
Vitamin D is significant for an enormous variety of bodily functions and has a really complex relationship with the metabolic system. Many alternative studies have found that vitamin D supplementation can improve glucose management, but diabetes authorities have been extremely reluctant to validate vitamin D as an efficient treatment. Despite an apparent wealth of evidence in favor of prioritizing vitamin D levels, most experts consider that science stays largely unconvincing.
In 2022, after a significant study showed that vitamin D supplementation had no impact on bone health — considered one of the few vitamin D advantages that was widely accepted as legitimate — The Recent England Journal of Medicine published an editorial (PDF) arguing that doctors should stop screening vitamin D levels and that folks should “stop taking vitamin D supplements to forestall major diseases or extend life.”
To be clear, severe vitamin D deficiency can have real consequences, similar to rickets and osteomalacia, and supplementation should be essential for certain people, similar to infants, breastfeeding moms, or those with conditions that cause nutrient malabsorption. Individuals with darker skin produce less vitamin D in sunlight and due to this fact usually tend to have lower amounts of vitamin D in circulation — Black Americans, for instance, are at a sharply elevated risk of vitamin D deficiency.
Major authorities similar to the Centers for Disease Control and Prevention and the National Institutes of Health proceed to treat vitamin D as a nutrient of concern, making broad recommendations for vitamin D intake. Alternatively, there’s also a downside to excessive vitamin D supplementation: vitamin D toxicity.
The Bottom Line
Studies linking low vitamin D levels with diabetes and diabetic retinopathy keep piling up, but we still don’t know if the connection is real. Many experts recommend that folks each with and without diabetes should prioritize vitamin D intake — whether through healthy eating, getting sunlight, or using supplements. The evidence of advantages, nevertheless, is shaky. In the event you’re concerned, consider asking your doctor in case you must be monitoring your vitamin D levels.