Posted on August 01, 2017

Ensuring and maintaining the required level of vitamin D is important for supporting bone, teeth, muscle, and immune health in children and adults, noted a HMC expert.

Dr. Mahmoud Zirie, Senior Consultant and Head of HMC’s Endocrinology and Diabetes Division said: “Maintaining healthy levels of vitamin D has been shown to be an important part of overall health as the vitamin helps the body absorb calcium from food. In older adults, a daily dose of vitamin D and calcium helps to prevent fractures and brittle bones. Children need vitamin D to build strong bones and prevent rickets, which causes bowlegs, knock-knees and weak bones.”

He noted that research suggests adequate amounts of vitamin D in the blood can play a role in the prevention and treatment of a number of different conditions, including Type 1 and Type 2 diabetes, hypertension, glucose intolerance, and multiple sclerosis. According to Dr. Zirie, the most accurate way to measure how much vitamin D is in the body is the 25-hydroxy vitamin D blood test. “A level of 30 nanograms/milliliter to 50 ng/mL is considered adequate for healthy people. A level less than 12 ng/mL indicates vitamin D deficiency,” he said.

Dr. Zirie explained that people commonly at risk of a vitamin D deficiency include those with inadequate sun exposure, limited oral vitamin D intake, or impaired intestinal absorption. “A vitamin D deficiency can occur if someone’s exposure to sunlight is limited. People may be at risk of deficiency if they are homebound, live in northern latitudes, wear long robes or head coverings for religious reasons, or have an occupation that prevents sun exposure,” he said. “Those with dark skin are also at risk. The pigment melanin reduces the skin's ability to make vitamin D in response to sunlight exposure. Some studies show that older adults with darker skin are at high risk of vitamin D deficiency,” he stated.

“Many people can also be at risk of developing a vitamin D deficiency as they age because their kidneys cannot convert vitamin D to its active form and the digestive tract cannot adequately absorb vitamin D,” said Dr. Zirie. He mentioned that certain medical problems, including Crohn's disease, cystic fibrosis, and celiac disease, can affect the intestine's ability to absorb vitamin D from the food we eat. “Obese individuals are also at risk of being deficient in vitamin D which is extracted from the blood by fat cells. People with a body mass index of 30 or greater often have low blood levels of vitamin D,” he pointed out.

Dr. Zirie noted that a vitamin D deficiency can occur if people do not consume the recommended level of the vitamin. He stressed that individuals who follow a strict vegan diet are susceptible to vitamin D deficiency because most of the natural sources of vitamin D are animal-based. “Vitamin D is produced by exposing the skin to ultraviolet B radiation from the sun or can be obtained from dietary sources such as oily fish including salmon, swordfish or mackerel.  Other fatty fish such as tuna and sardines have some vitamin D but in much lower amounts. Small amounts are also found in egg yolks, beef liver and fortified foods like cereal and milk,” explained Dr. Zirie.

He noted that while eating vitamin D-rich foods is the best way to get the vitamin, it can also be obtained through supplements. “There are two kinds of supplements - D2 (ergocalciferol), which is the type found in food, and D3 (cholecalciferol), which is the type made from sunlight. They're produced differently, but both can raise vitamin D levels in the blood. Most multivitamins have 400 IU of vitamin D,” he explained. While there are often no symptoms of mild vitamin D deficiency, symptoms can include difficulty thinking clearly, bone pain, frequent bone fractures, muscle weakness and unexplained fatigue.