Vitamin D (25-OH) Blood Test Kit

Despite its name, vitamin D is actually a hormone produced by your skin when exposed to sunlight. It must be converted into 25-hydroxyvitamin D (25 OH), the major circulating form, which is the most accurate indicator of vitamin D supply to your body. Vitamin D is essential for healthy bones and teeth (it helps your body absorb calcium), muscle function, immune system regulation, and mental health. Low vitamin D symptoms include muscle weakness, bone pain, mood changes, fatigue, and increased susceptibility to infections. Many people in the UK have low levels, particularly those with darker skin, people who spend limited time outdoors, older adults, those who cover their skin for religious or cultural reasons, and people who are overweight (vitamin D is stored in fat tissue). Small amounts can be obtained from dietary sources such as oily fish (salmon, mackerel, sardines), egg yolks, and fortified foods, but most people in the UK cannot get enough from diet alone. Supplementation is often needed to achieve and maintain optimal levels, particularly during autumn and winter. Low levels should be discussed with your GP, who may recommend supplementation.