Side Effects of Too Much Vitamin D
Vitamin D is a fat-soluble vitamin. This means it’s stored in body fat and can remain in your body for a long time.
If you choose to take vitamin D supplements, be sure to stick to a dosage that is within the recommended range. Do not take more unless you’re monitored by a health care provider and instructed to take more, perhaps because a blood test has revealed you’re deficient. “Vitamin D toxicity” (when you’ve taken too much vitamin D) can potentially develop if someone takes more than 300,000 IU in a 24-hour period or more than 10,000 IU of vitamin D per day for months.
In order to prevent side effects of vitamin D you should avoid taking very high doses of vitamin D in supplement form, such as 10,000 IU per day for more than several weeks in a row. While supplements are necessary and beneficial in many cases, it’s ideal to get the vitamin D you need directly from sunlight, particularly from exposing your bare skin to the sun for 10–20 minutes most days of the week.
You can also safely increase your vitamin D level by eating vitamin D-rich foods, such as fish, eggs and raw milk.
Side Effects of Low Vitamin D
Low vitamin D is also called vitamin D deficiency. Believe it or not, an estimated 1 billion people worldwide are affected by vitamin D deficiency, and many more are suspected to be at least marginally low in this essential vitamin. Side effects of low vitamin D can include:
- Fatigue
- Osteoporosis or bone fractures
- Higher risk for cardiovascular disease
- High blood pressure
- Higher risk for certain types of cancer
- Autoimmune diseases
- Depression
- Insomnia
- Arthritis
- Higher risk for diabetes
- Asthma
- Chronic pain
- Susceptibility to infectious diseases
Why is vitamin D deficiency so common? The main reason is many people today don’t spend enough time in the sun, due to factors like working indoors or wearing sunblock, and also don’t eat enough foods that supply vitamin D (like fish). You’re at an increased risk for having low vitamin D levels if:
- You have dark skin
- You’re an older adult over 70 (since the production of vitamin D from the skin decreases with age). Infants, children, and older adults are all at risk for low vitamin D
- You spend little time outdoors or always wear sunscreen when exposed to sunlight
- You’re a shift worker, health care worker or another “indoor worker,” which means you get little outdoor time and sunlight exposure
- You’re overweight or obese (since vitamin D can accumulate in body fat)
- You are a nursing home resident or hospitalized patient
- You have a health condition such as celiac disease, Crohn’s disease or cystic fibrosis that interferes with absorption and processing of vitamin D in the intestines, kidneys or liver
- Breast-fed infants are also at risk for vitamin D deficiency, which is why supplementing is recommended