Scientists from Brigham and Women’s Hospital have found that supplementation with vitamin D3 or marine omega-3 fatty acids does not reduce the risk of frailty in older adults.
The study, led by Ariela Orkaby and colleagues, was published in JAMA Network Open.
Frailty is an aging-related syndrome marked by physiological decline and increased vulnerability to adverse health outcomes.
Clinically, it is defined by meeting at least three of five criteria: weakness, slowness, low physical activity, self-reported exhaustion, and unintentional weight loss.
Vitamin D is a fat-soluble vitamin found naturally in a small number of foods, added to fortified foods, and available through supplements. It is also produced in the body when sunlight triggers vitamin D synthesis in the skin.
Vitamin D supports calcium absorption in the gut and helps maintain appropriate blood levels of calcium and phosphate, which are essential for normal bone mineralization. It also plays key roles in muscle function, immune health, and overall well-being.
Vitamin D2 comes from plants and yeast, while vitamin D3 is found in animal sources and is the form typically used in supplements.
Omega-3 fatty acids are essential fats that must be obtained from food. They are vital components of cell membranes and influence how cell receptors function.
Omega-3s also serve as building blocks for hormones that regulate blood clotting, inflammation, and the contraction and relaxation of blood vessels.
Foods rich in omega-3s include fish, vegetable oils, nuts (especially walnuts), flax seeds, flaxseed oil, and leafy green vegetables.
To test whether supplementation with vitamin D3 and omega-3 fatty acids could reduce the risk of frailty, researchers conducted a large clinical study involving more than 25,000 adults aged 50 years or older.
Participants had no history of cancer or heart disease and provided detailed information on their frailty status.
They were recruited from all 50 U.S. states between November 2011 and March 2014 and followed through December 31, 2017.
Participants were randomly assigned to take vitamin D3 (2,000 IU/day), marine omega-3 fatty acids (1 g/day), both supplements, or a placebo. After five years of treatment, the researchers found that neither vitamin D3 nor omega-3 supplementation had a strong effect on changes in frailty scores compared with placebo.
These findings do not support the routine use of vitamin D3 or omega-3 fatty acids to prevent frailty in generally healthy older adults. However, the researchers note that more studies are needed to determine whether vitamin D3 supplementation might benefit people who are vitamin D deficient.
