Are you getting enough vitamin D?
If you’re like most women in the U.S., you may not be.
We’re supposed to get our daily supply of this important nutrient from the sun and from food, but according to recent studies, many of us are falling short.
· Worldwide pandemic: In 2008, researchers reported: “Vitamin D deficiency is now recognized as a pandemic.” They cited lack of sun exposure as part of the reason, and noted:” “Very few foods naturally contain vitamin D, and foods that are fortified with vitamin D are often inadequate to satisfy either a child’s or an adult’s vitamin D requirement.”
· Three-quarters of Americans coming up short: In 2009, researchers reported that three-quarters of Americans were deficient in vitamin D. This was a startling increase, as between 1988 and 1994, only 45 percent of those studied (over 18,000) were deficient. African Americans were especially low, with just three percent having recommended levels, compared to 12 percent in the previous study period. Researchers considered 30 nanograms per milliliter (ng/mL) of blood to be adequate.
· Deficiency and disease: A 2011 study looked at vitamin D levels in nearly 4,500 participants and found that over 41 percent were deficient. Over 82 percent of black Americans were deficient, and nearly 70 percent of Hispanics. Researchers also noted that those who were deficient were more likely to have low levels of HDL “good” cholesterol and to be obese and in poor health.
These studies are concerning because low levels of vitamin D have been linked to a number of health problems—some specific to women.
What is Vitamin D For?
The body needs vitamin D to do the following:
· Maintain strong bones
· Support muscle strength and function
· Keep the immune system working well
· Deliver nerve messages from the brain to the body
· Maintain a healthy heart and blood circulation
· Protect cells from damage
Severe vitamin D deficiency can cause a condition called “rickets” in children (softening of the bones) and osteomalacia (a similar condition) in adults. This type of deficiency is rare today in the U.S., however.
What is more common is having vitamin D levels that aren’t so low they cause a severe deficiency, but are still far below optimal levels. If we rarely go outside, use sunscreen all the time, or live in the northern latitudes where the sun may be scarce in winter, we can end up not getting enough.
The recommended daily allowance (RDA) for vitamin D is:
· 600 IU for those 1-70 years of age, and for pregnant and breastfeeding women
· 800 IU for those 71 years of age and older
In most studies examining vitamin D levels in blood, researchers consider 30 ng/mL to be adequate, and levels lower than that to show a deficiency. Many researchers today consider 50-60 ng/ml to be the optimal range for physical and mental health.
The body makes vitamin D when we expose our skin to the sun (without sunscreen). We also get some of the nutrient from food, but not enough to meet our daily requirements.
7 Concerns When Women Don’t Get Enough
When vitamin D levels drop below the recommended 30 ng/mL level, women can be at risk for the following health issues:
1. Cardiovascular disease: The heart suffers without enough vitamin D. A recent study looked at vitamin D levels in over 160,000 women and 86,000 men and found that those with lower levels of the vitamin were more at risk of dying from cardiovascular disease, stroke, and heart attack. Among those who did die, nearly 80 percent had low levels below 28 ng/mL. A third study showed that low vitamin D levels were linked to an increased risk of suffering severe stroke, and to poor health in those who had survived stroke.
2. Depression: Studies have linked low levels of vitamin D to depression in otherwise healthy young women. In 2015, for example, researchers tested 185 college students between the ages of 18 and 25 and found that those with lower levels of vitamin D were more likely to have significant symptoms of depression. In another study published this year, participants looked at over 5,000 individuals aged 30-79 years and found that those with higher levels of vitamin D in their blood had a reduced risk of depression.
3. Alzheimer’s disease: It’s only recently that scientists have begun to realize the connection between vitamin D and a healthy brain. In a 2014 study, researchers tested over 1,600 adults aged 65 and older, and found that those who were moderately deficient in vitamin D were more than twice as likely to develop dementia and Alzheimer’s disease.
4. Cancer: Vitamin D seems to not only help prevent cancer, but to increase chances of survival once someone has it. A 2015 study, for example, found that patients with colorectal cancer who had higher levels of vitamin D in their bloodstream survived longer, on average, than patients with lower levels. Another recent study found similar results in patients with lymphoma. The National Cancer Institute states that some studies have reported a possible link between vitamin D and cancer risk, with results showing that the nutrient may slow or prevent the development of cancer.
5. Preterm birth: Mothers who are deficient in vitamin D, particularly during early pregnancy, were more likely to deliver early, preterm, than women with adequate levels of the vitamin, according to a 2015 study. Pregnant women are advised to get 600 IUs of vitamin D daily.
6. Pregnancy complications: Moms who don’t get enough vitamin D may also be at risk for developing high blood pressure and gestational diabetes. Particularly moms who live in northern climates should be sure they’re getting enough through supplements.
7. Hip fractures: As vitamin D is important for the maintenance of healthy bone, it becomes extremely important to women after menopause. A 2003 study found that postmenopausal women with adequate levels of vitamin D were less likely to suffer hip fractures caused by osteoporosis. Researchers added that intake of milk didn’t help—women needed supplements to get enough.
A low level of vitamin D has also been linked to an increased risk of type 2 diabetes and fertility problems.
Can You Get Too Much?
Though there have been some studies in the past suggesting that we can get too much vitamin D, but more recent research makes it clear that our concerns should be about not getting enough, not getting too much.
Turns out that “vitamin D toxicity” (toxic effects from too much of the nutrient) is extremely rare. Researchers from the Mayo Clinic analyzed information from over 20,000 participants, and found that those with a so-called “high” level of vitamin D (defined as 50 ng/mL or more) was only 8 percent, and even those people rarely experienced any problems because of it.
The recommended upper limit of the vitamin is 4,000 IUs a day.
How to Get More
If you find that you’re low on this important nutrient, here are some tips to boost your intake:
· Spend 15 minutes daily in the sunshine without sunscreen.
· Take a daily supplement of 600-800 IUs.
· Eat more fatty fish, beef liver, cheese, and egg yolks.