Vitamin D plays an important role in health, including the development and calcification of the bones. In this guide, OBGYN Dr. Gleaton talks about vitamin D deficiency.
Vitamin D is a fat-soluble vitamin naturally present in a few foods, or available as a dietary supplement. You may know vitamin D as the “sunshine vitamin” because it is produced in your body when ultraviolet (UV) rays from sunlight strike the skin and trigger vitamin D synthesis.
Vitamin D is one of the more important vitamins. It promotes calcium absorption and is critical for bone growth. Without sufficient vitamin D, bones can become thin, brittle, or misshapen. Vitamin D is also important for reducing inflammation, and supporting immune function.
What is vitamin D deficiency? How common is it?
Vitamin D deficiency means that you do not have enough vitamin D in your body. The main reasons for low levels of vitamin D are lack of vitamin D in the diet, lack of sun exposure, or the inability to absorb vitamin D. Although there is no formal definition of vitamin D deficiency, most groups use the following values in adults:
- A normal level of vitamin D is defined as a 25(OH)D concentration greater than 20 ng/mL (50 nmol/L)
- Vitamin D insufficiency is defined as a 25(OH)D concentration of 12 to 20 ng/mL (30 to 50 nmol/L)
- Vitamin D deficiency is defined as a 25(OH)D level less than 12 ng/mL (30 nmol/L)
Vitamin D deficiency is more common during pregnancy, especially for Black women. One study found that 54% of Black pregnant women are vitamin D insufficient (also known as “subclinical” deficiency) and 29% are deficient. For white pregnant women, 5% were deficient and 42% were insufficient.
Vitamin D deficiency is more common during pregnancy, especially for Black women.
Overall, almost a quarter of Americans have vitamin D insufficiency For this group, there are usually no visible signs or symptoms.
Am I at risk for vitamin D deficiency during pregnancy?
Vitamin D deficiency is common during pregnancy, especially among high-risk groups such as:
- Vegetarians and vegans
- People with milk allergy or lactose intolerance
- People with limited sun exposure due to location, protective clothing, or use of sunscreen
- People with darker skin
- People with conditions that limit fat absorption
- People who are obese or have undergone gastric bypass surgery
- People taking medications that accelerate the metabolism of vitamin D (such as phenytoin)
- People with malabsorption, including inflammatory bowel disease (IBS) and celiac disease
During pregnancy, it is recommended to get 600 IU vitamin D daily, with an upper limit of 4,000 IU/day.
Breastfeeding and vitamin D deficiency
Although rare, exclusively breastfeeding for a longtime without vitamin D supplementation can cause rickets in infants. In one Minnesota county, they found the incidence rate of rickets in children under three to be 24.1 per 100,000, and almost all the children had been breastfeed without vitamin D supplementation. The American Academy of Pediatrics (AAP) recommends 400 IU/day vitamin D supplements for breastfed infants starting shortly after birth and lasting until they are weaned.
It is recommended that breastfeeding mothers get 600 IU vitamin D daily, with an upper limit of 4,000 IU/day.
What are symptoms of vitamin D deficiency?
Most people with mild or moderate vitamin D deficiency have no symptoms. For those with more severe vitamin D deficiency, symptoms can include:
- Bone pain
- Muscle weakness or aches
- Mood changes.
Unless you are at high risk for vitamin D deficiency, it is unlikely your provider will test for it. If you think you are at high risk, I recommend bringing it up with your provider, especially if you're pregnant.
How is vitamin D deficiency treated during pregnancy?
If vitamin D deficiency is diagnosed during pregnancy, most experts agree that 1,000–2,000 IU per day of vitamin D supplement is safe (our Vitamin D3 gummy has 1,000 IU per gummy). Don’t forget to count the level of vitamin D already in your prenatal vitamin, to ensure that you don’t go over the upper limit of 4,000 IU/day. And always make sure to discuss your prenatal dietary supplement routine with your provider who can give further guidance.
How can I raise my vitamin D levels quickly?
The good news about vitamin D deficiency is that it’s relatively easy to reverse. Here are some ways to boost your vitamin D levels:
- Take a vitamin D3 supplement
- Get some sunshine
- Get a sunlamp
- Add vitamin-D rich foods to your diet, such as salmon, tuna, milk, egg yolks, and mushrooms
Can taking vitamin D improve mood and depression?
Although research shows a correlation between vitamin D deficiency and depression, it is unclear whether vitamin D deficiency is the result or cause of depression. Furthermore, research is insufficient to claim that vitamin D can improve mood or symptoms of depression. In one randomized clinical trial of over 18,000 adults, those who took a vitamin D3 supplementation did not have a statistically significant difference in depression or mood over a 5-year period. If you have symptoms of depression, please talk to a professional.
- Vitamin D promotes calcium absorption and is critical for bone growth. It is also important for reducing inflammation, and supporting immune function.
- Vitamin D deficiency is more common during pregnancy.
- During pregnancy and breastfeeding, it is recommended to get 600 IU vitamin D daily, with an upper limit of 4,000 IU/day.
- If vitamin D deficiency is diagnosed during pregnancy, most experts agree that 1,000–2,000 IU per day of vitamin D supplement is safe.