25 - Hydroxyvitamin D

Vitamin D toxicity is a rare but potentially serious condition that occurs when you have excessive amounts of vitamin D in your body. Vitamin D toxicity is usually caused by megadoses of vitamin D supplements—not by diet or sun exposure. The main consequence of vitamin D toxicity is a buildup of calcium in your blood, which can cause poor appetite, nausea, and vomiting.

Vitamin D is essential for strong bones, because it helps the body use calcium from the diet. Traditionally, vitamin D deficiency has been associated with rickets, a disease in which the bone tissue doesn’t properly mineralize, leading to soft bones and skeletal deformities. Another potential issue stemming from vitamin D deficiency is osteoporosis, which is seen most prevalent in the elderly—particularly women. This is because all our bones naturally lose calcium over a lifetime, but the process of creating a healthy baby adds an extra toll on women’s bones. Additionally, low blood levels of the vitamin have been associated with the following:

- Increased risk of cardiovascular disease

- Cognitive impairment in older adults

- Severe asthma in children

- Cancer

Vitamin D deficiency can occur for a number of reasons, including:

- Not consuming enough of the vitamin in the diet, particularly for vegans

- The kidneys not being able convert vitamin D to its active form

Vitamin D is well known for the role it plays in regulating calcium and phosphorus to maintain bone health. Vitamin D insufficiency has been linked to depression and Seasonal Affective Disorder, neurological autoimmune processes, and in preventing on-going inflammation that damages tissue.

Vitamin D, frequently called the “sun vitamin,” is an essential component of the systems that our bodies use to keep bones and teeth strong. It also has important, emerging roles in immune function and cancer prevention. We have natural processes that regulate vitamin D production from the sun so extremely high levels of it are rare. Deficiency can cause a number of issues including weak bones, called osteomalacia.

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There is no consensus in the literature regarding optimal levels of 25-Hydroxyvitamin D. Higher levels of 25-Hydroxyvitamin D may be concerning in patients with renal failure. Levels below 30 ng/mL are considered insufficient by most medical associations.