Toxicity Symptoms for vitamin D

What are toxicity symptoms for vitamin D?

Excessive intake of vitamin D can be toxic, and toxicity of vitamin D can come from either its plant-based (D2) or animal-based (D3) form. Symptoms of toxicity include loss of appetite, nausea, vomiting, high blood pressure, kidney malfunction, and failure to thrive. However, it is also important to note that vitamin D deficiency poses a far greater risk to the vast majority of individuals than vitamin D toxicity and that vitamin D toxicity from food intake is extremely unlikely. Less than one-third of all persons in the U.S. meet the Dietary Reference Intake level for vitamin D, and are far from consuming anything close to potentially toxic levels.

In 2010, the National Academy of Sciences set Tolerable Upper Intake Levels (ULs) for vitamin D as follows:

• infants, 0-6 months: 25 micrograms (1,000 IU) per day
• infants, 6-12 months: 38 micrograms (1,500 IU) per day
• children, 1-3 years: 63 micrograms (2,500 IU) per day
• children, 4-8 year: 75 micrograms (3,000 IU)per day
• children and adolescents, 9-18 years: 100 micrograms (4,000 IU) per day
• adults, 19 years and older: 100 micrograms (4,000 IU) per day
• pregnant and lactating women, 100 micrograms (4,000 IU) per day.

While these toxicity limits are based on credible data, they do not attempt to address the issue that is posed by higher vitamin D intake amounts potentially needed to offset chronic deficiency of this vitamin. Clinical research has clearly shown that vitamin D supplementation in the range of 1,000-2,000 IU per day is unable to restore optimal vitamin D levels in many individuals with chronic vitamin D deficiency. In many cases, individuals with chronic vitamin D deficiency will need to exceed the vitamin D Upper Limits established by the National Academy of Sciences in order to bring the levels of hydroxyvitamin D in their blood up to optimal levels. Remedy of chronic vitamin D deficiency will also typically require supplementation of vitamin D since everyday food intake is typically unable to provide deficiency-offsetting amounts of this vitamin. Steps to remedy chronic vitamin D deficiency should always be taken in consultation with a licensed healthcare provider who is able guide and monitor changes in blood levels of vitamin D.

Individuals with primary hyperparathyroidism (overactivity of the parathyroid gland not caused by vitamin D deficiency) are at increased risk for vitamin D toxicity and should not take supplemental vitamin D without consulting a physician.