Vitamin a d e
Pro Research Analysisby 
Searched over 200M research papers
The Role of Vitamins A, D, and E in Health and Disease
Vitamin A and Its Health Implications
Vitamin A and Tuberculosis
Vitamin A plays a crucial role in immune function and vision. Research indicates that individuals with tuberculosis (TB) have significantly lower levels of vitamin A compared to healthy controls. A meta-analysis found that the standardized mean difference (SMD) in blood vitamin A concentration between TB patients and control subjects was -0.96, suggesting a strong negative association between vitamin A levels and TB.
Vitamin A in Preterm Infants
In preterm infants, vitamin A supplementation is essential for growth and development. A longitudinal study showed that plasma concentrations of vitamin A increased steadily over three months in both breast-fed and formula-fed preterm infants receiving daily supplementation, although levels did not reach those seen in term infants.
Vitamin A Absorption with Vitamin E
The absorption of vitamin A can be influenced by the presence of vitamin E. A study on children found that high doses of vitamin E (500 mg) significantly increased the intestinal absorption of a massive dose of vitamin A, although it also increased urinary excretion.
Vitamin D and Its Health Implications
Vitamin D and Tuberculosis
Vitamin D is vital for bone health and immune function. Similar to vitamin A, individuals with TB have significantly lower levels of vitamin D. The meta-analysis reported an SMD of -0.53 for blood vitamin D concentration in TB patients compared to controls, and a higher odds ratio (OR) of vitamin D deficiency in TB patients (OR: 2.29).
Vitamin D in Preterm Infants
For preterm infants, vitamin D supplementation is crucial for bone development. The same longitudinal study on preterm infants showed that plasma concentrations of 25-hydroxyvitamin D increased to levels comparable to those in term infants after three months of supplementation.
Vitamin E and Its Health Implications
Vitamin E and Tuberculosis
Vitamin E, known for its antioxidant properties, is also found to be lower in TB patients. The meta-analysis indicated an SMD of -0.34 for blood vitamin E concentration in TB patients compared to healthy controls, suggesting a negative association.
Vitamin E in Preterm Infants
In preterm infants, vitamin E supplementation is important for preventing oxidative stress. The longitudinal study demonstrated that plasma concentrations of vitamin E increased over time with supplementation, although they did not reach the levels seen in term infants.
Vitamin E and Cognitive Function
Vitamin E has been studied for its potential benefits in cognitive function, particularly in Alzheimer's disease (AD) and mild cognitive impairment (MCI). A Cochrane review found no significant evidence that vitamin E improves cognitive function or prevents progression from MCI to AD. However, it may slow functional decline in AD patients without increasing the risk of serious adverse events or mortality.
Conclusion
Vitamins A, D, and E play significant roles in various health conditions, including tuberculosis, preterm infant development, and cognitive function. Lower levels of these vitamins are associated with TB, and supplementation in preterm infants shows beneficial increases in plasma concentrations. While vitamin E may aid in slowing functional decline in AD, its overall impact on cognitive function remains inconclusive. Further research is needed to fully understand the therapeutic potential and optimal supplementation strategies for these essential vitamins.
Sources and full results
Most relevant research papers on this topic