Safety of Vitamin D3

Often called the “sunshine vitamin,” vitamin D plays a major role in many of the body's functions. Blood levels of vitamin D also stand out as reliable predictors of a number of chronic diseases, as pointed out by Dr Joseph Mercola, a physician certified by the American College Osteopathic General Practitioners and a best-selling author. Mercola suggests that you use vitamin D3 as the body prefers this form over vitamin D2.

Vitamin D3 Uses

Vitamin D3, also called cholecalciferol, is produced when UVB rays come into contact with your skin. You can also obtain the nutrient from food supplies—cod liver oil represents the best source. Vitamin D exhibits a wide range of effects in the human body beyond simply contributing to bone health. It improves insulin sensitivity, boosts dopamine function, and reduces allergic reactions while boosting overall immune function.

Vitamin D Deficiency

While many textbooks list ricketts as the consequence of vitamin D deficiency, Mercola lists vitamin D deficiency as a causative factor in the development of cardiovascular disease and cancers. The rate of vitamin D deficiency has increased heavily due to the reduced time that most individuals spend outdoors in the sunshine and because so few people take cod liver oil.

Safety Concerns

Vitamin D3 supplements have become more popular in recent years as a way of maintaining blood levels of this key nutrient, but some experts have voiced their concern over potential toxicity of taking such products. The National Institutes of Health, which suggests an intake of 400 IU per day, list the symptoms of vitamin D toxicity as nausea, vomiting, poor appetite, weakness and weight loss. However, the organization does not state how much vitamin D3 you need to consume before toxicity occurs; the organization also makes it clear that patients taking 50,000 IU of vitamin D3 daily for eight weeks did not display any signs of toxicity.

Studies

Dr John Cannell, a scientific researcher and the head of the Vitamin D Council, argues that government health officials have set their recommendations for the vitamin at an overly cautious level. He explains how the adult body requires around 5,000 IU per day of vitamin D3 to maintain adequate stores and even more when addressing a long-term deficiency. A study published in the "American Journal of Clinical Nutrition" concluded that healthy men use around 3,000 to 5,000 IU of vitamin D3 each day, while a more recent study in the same journal agreed that 3,800 IU each day represented the ideal amount to ensure optimum blood levels.

Expert Insight

Dr Cannell makes recommendations for those looking to address their vitamin D levels. If you believe you may be deficient in this nutrient, he suggests taking 5,000 IU each day for three months and then getting a blood test for a compound called hydroxy-vitamin D. Based on the results, you may have to adjust your dosage.