Vitamin D deficiency in women is quite common. Women Fitness brings a complete resource on how to overcome deficiency of this vital sunshine vitamin in human body.
Vitamin D is important for bones, muscles and overall health and more so in women. It is made in our bodies through a series of processes that start when our skin is exposed to the sun’s ultraviolet (UV) radiation. Vitamin D is essential for bone health. Recent research suggests it may have other benefits, too, such as protecting against colds and fighting depression. The good news is that most people get enough vitamin D, according to the Institute of Medicine (IOM).
However, if you don’t spend enough time in the sun or if your body has trouble absorbing the vitamin, you may not get enough. Scientists say that up to 41 percent of American adults don’t get sufficient levels of this crucial nutrient — which may raise their risk of heart disease, obesity, depression, diabetes, osteoporosis, and some cancers.
Plus, a September 2015 study published in JAMA Neurology found that deficiency in the vitamin was associated with faster decline in certain cognitive functions — like recalling past events and performing mental tasks like reasoning and problem solving — in older adults. So exactly how much vitamin D do you need? The National Institutes of Health recommends that adults between 19 and 70 years old get at least 600 international units (IUs) of vitamin D per day, an amount that may be tough to get from the sun alone. If you think you may be deficient — sleepiness, crankiness, and high blood pressure are all clues that you could be.
Vitamin D may be known as the sunshine vitamin, but according to a new survey by Prevention and supplement company Centrum, few of us think to look for it in the fridge—and that’s a big mistake.
“The sun is not strong enough for the body to make vitamin D from October to May, especially for those living north of Atlanta,” says Althea Zanecosky, RD, a spokesperson for the American Dietetic Association. That’s probably why nearly half of people tested at winter’s end were low on vitamin D, according to a University of Maine study.
Compounding the problem is our vigilant use of sunscreen; SPF 15 blocks 93% of UVB rays, the type our bodies use to make D. Skin also has a harder time producing vitamin D with age. All this adds up to a big problem, as evidence continues to mount that the vitamin, long associated with bone health, also helps to regulate the immune system, lower blood pressure, protect against depression, and reduce risk of type 2 diabetes, high blood pressure, and several kinds of cancer. A 2014 study from the University of California-San Diego School of Medicine also found that people with low vitamin D levels were twice as likely to die prematurely.
So are you getting enough D? Probably not. The Institute of Medicine has set the Recommended Dietary Allowance (RDA) of vitamin D at 600 international units (IU) for everyone under the age of 70. (It’s 800 IU for adults 70+.) But many experts believe that’s too low. “There is talk that the RDA may be increased,” says Zanecosky. “Many physicians are now advising 2,000 mg daily for those with low blood levels.”
Many respondents in the Prevention and Centrum recent nutrient survey were rightfully concerned they weren’t getting enough D, with 22% actively looking for it in foods. But just 9% knew that salmon is a good natural source of the vitamin, and only 5% recognized fortified tofu as one, too.
Many women are at risk of low vitamin D, particularly those with naturally very dark skin and those with little sun exposure. A balanced approach is required to ensure some sun exposure for vitamin D while minimising the risk of skin cancer.
Tips to help you get enough vitamin D
Take a balanced approach to sun exposure. UV radiation from the sun is the best natural source of vitamin D, but too much sun exposure can increase your risk of skin cancer.
From May to August in Victoria, get two to three hours of midday sun exposure per week. In Victoria, UV levels fall below three from May to August. At this time, most people need two to three hours of midday winter sun exposure to the face, arms, hands (or equivalent area of skin) over the course of a week. People with naturally very dark skin may require three to six times this amount of sun.
From September to April in Victoria, get a few minutes of mid-morning or mid-afternoon sun exposure each day. In Victoria, UV levels reach three and above for much of the day from September to April, and sun protection is required. At this time, most people need just a few minutes of mid-morning or mid-afternoon sun exposure to the face, arms, hands (or equivalent area of skin). People with naturally very dark skin, may require three to six times this amount of sun.
Use a combination of sun protection measures between September and April, when UV levels are three and above. Use a combination of clothing, sunscreen, hats, shade and sunglasses. Sunscreen use should not put you at risk of vitamin D deficiency.
Never use a solarium to increase vitamin D. A solarium gives off dangerous UV radiation, increasing the risk of skin cancer.
Speak to your doctor if you are at risk of low vitamin D. You might be at risk of low vitamin D if you have naturally very dark skin, get little or no sun exposure, have a medical condition that affects vitamin D metabolism, or take certain medications (for example, those that increase the breakdown of vitamin D). Breastfed babies who fall into the above categories, or have mothers with low vitamin D, can also be at risk.
Exercise daily. Regular exercise assists with production of vitamin D.
Eat enough calcium. Vitamin D and calcium work together to make your bones strong. Make sure you get enough calcium by including a selection of dairy products, leafy vegetables, fish, tofu, Brazil nuts and almonds in your diet.
Eat foods rich in vitamin D. Good sources include eggs, liver, and fatty fish such as mackerel, herring and salmon. Some margarines and low-fat milks have added vitamin D. Food, however, only makes a small contribution (approximately 10 per cent) to the body’s overall vitamin D levels and it is difficult to get enough vitamin D from diet alone.
Speak to your doctor before taking supplements. Vitamin D supplements may be helpful for some people, but you should speak with your doctor first and take them strictly as directed.
Natural Sources of Vitamin D
- Wild-caught fish (425 IU in 3 oz salmon, 547 IU in 3 oz mackerel)
- Beef or calf liver (42 IU in 3 oz)
- Egg yolks (41 IU per egg)
- Canned fish (154 IU in 3 oz tuna, 270 IU in 3.5 oz sardines)
- Shiitake mushrooms (40 IU in 1 cup)
Fortified Sources
- Milk: whole, nonfat or reduced fat (100 IU in 8 oz)
- Yogurt (80–100 IUs in 6 oz)
- Almond milk (100 IU in 8 oz)
- Pudding made with milk (49-60 IUs in ½ cup)
- Orange juice (137 IU in 1 cup)
- Breakfast cereals (50–100 IUs in 0.75–1 cup)
- Fortified tofu (80 IU in 3 oz)
- Oatmeal (150 IU in 1 packet)
- Cheese (40 IU in 1 slice)
- Eggnog (123 IU in 8 oz)
- Margarine (25 IU in 1 teaspoon)
Note: Not all brands are vitamin-D fortified, so read labels carefully.
The two main ways to get vitamin D are by exposing your bare skin to sunlight and by taking vitamin D supplements. You can’t get the right amount of vitamin D your body needs from food.
The most natural way to get vitamin D is by exposing your bare skin to sunlight (ultraviolet B rays). This can happen very quickly, particularly in the summer. You don’t need to tan or burn your skin to get vitamin D. You only need to expose your skin for around half the time it takes for your skin to turn pink and begin to burn. How much vitamin D is produced from sunlight depends on the time of day, where you live in the world and the color of your skin. The more skin you expose the more vitamin D is produced.
You can also get vitamin D by taking supplements. This is a good way to get vitamin D if you can’t get enough sunlight, or if you’re worried about exposing your skin. Vitamin D3 is the best kind of supplement to take. It comes in a number of different forms, such as tablets and capsules, but it doesn’t matter what form you take, or what time of the day you take it.
Different organizations recommend different amounts of vitamin D supplement to take each day. The Vitamin D Council recommends taking larger amounts of vitamin D each day than other organizations, because smaller amounts aren’t enough to give you what your body needs. Most people can take vitamin D supplements with no problems. However, if you have certain health problems or take certain medicines, you may need to take extra care.
Your body gets most of the vitamins and minerals it needs from the foods that you eat. However, there are only a few foods that naturally contain any vitamin D. Most foods that contain vitamin D only have small amounts, so it’s almost impossible to get what your body needs just from food.
Because there are only small amounts of vitamin D in food there are only two sure ways to get enough vitamin D:
- Exposing your bare skin to sunlight to get ultraviolet B (UVB).
- Taking vitamin D supplements.
- Exposing your bare skin to sunlight (ultraviolet B)
Your body is designed to get the vitamin D it needs by producing it when your bare skin is exposed to sunlight. The part of the sun’s rays that is important is ultraviolet B (UVB).
This is the most natural way to get vitamin D.
Large amounts of vitamin D3 (cholecalciferol) are made in your skin when you expose all of your body to summer sun. This happens very quickly; around half the time it takes for your skin to turn pink and begin to burn. This could be just 15 minutes for a very fair skinned person, yet a couple of hours or more for a dark skinned person.
You don’t need to tan or to burn your skin in order to get the vitamin D you need. Exposing your skin for a short time will make all the vitamin D your body can produce in one day. In fact, your body can produce 10,000 to 25,000 IU of vitamin D in just a little under the time it takes for your skin to turn pink. You make the most vitamin D when you expose a large area of your skin, such as your back, rather than a small area such as your face or arms.
There are a number of factors that affect how much vitamin D your body produces when your skin is exposed to sunlight. These include the time of year and time of day, where you live in the world and the type of skin you have.
The amount of vitamin D you get from exposing your bare skin to the sun depends on:
- The time of day – your skin produces more vitamin D if you expose it during the middle of the day.
- Where you live – the closer to the equator you live, the easier it is for you to produce vitamin D from sunlight all year round.
- The color of your skin – pale skins make vitamin D more quickly than darker skins.
- The amount of skin you expose – the more skin your expose the more vitamin D your body will produce.
- The time of year and time of day
When the sun’s rays enter the Earth’s atmosphere at too much of an angle, the atmosphere blocks the UVB part of the rays, so your skin can’t produce vitamin D. This happens during the early and later parts of the day and during most of the day during the winter season.
The closer to midday you expose your skin, the better this angle and the more vitamin D is produced. A good rule of thumb is if your shadow is longer than you are tall, you’re not making much vitamin D. In winter, you’ll notice that your shadow is longer than you for most of the day, while in summer, your shadow is much shorter for a good part of the middle of the day.
The further you live away from the equator, the less vitamin D you can make during the winter, if at all.
The equator is an imaginary line on the Earth’s surface halfway between the North Pole and South Pole, which divides the Earth into the Northern Hemisphere and Southern Hemisphere. The further away you are from the equator, the more of an angle the sun will hit the atmosphere at, and the less UVB there will be available for you to produce vitamin D, particularly during the winter time.
In the summer, when the Earth rotates, the angle improves and more UVB reaches the places far away from the equator, allowing you to produce vitamin D outside of winter months.
For example, in the southern United States, in places like Florida, your body can produce vitamin D most of the year, while in more northern places, like New York City or Boston, you can’t produce much vitamin D from November through March. If you live even further north, like in Edmonton, Canada, you can’t produce vitamin D from October through
April. These times are even longer (by a month or two) if you’re skin type is darker.
Women living in the Southern Hemisphere
In Buenos Aires, you can’t produce vitamin D in June. In Cape Town, you can’t produce much vitamin D between mid-May and August. If you live as far south as the bottom tip of Chile and Argentina, you can’t produce vitamin D April through October! If you’re skin is darker, these windows are even longer by a month or two.
Women living in Johannesburg can produce vitamin D all year round.
Your skin type
Melanin is a substance that affects how light or dark your skin color is. The more melanin you have, the darker your skin color. The amount of melanin you have in your skin affects the amount of vitamin D you can produce.
Melanin protects against skin damage from too much UVB exposure, so darker skins with more melanin allow less UVB to enter the skin. With less UVB getting through the skin, less vitamin D is produced each minute. This is why if you’re dark skinned, you need more sun exposure to make vitamin D than if you’re fair skinned.
The paler your skin type the more easily your skin can produce vitamin D. So, if you have skin type I to III, you produce vitamin D more quickly than if you have skin type IV to VI.
For example, if you have skin type I, it might take around 15 minutes of sun exposure to get the vitamin D you need, while if you have skin type V or VI, it might take up to six times longer (up to 2 hours).
Because of all these factors – your skin type, where you live and the time of day or season – it can be difficult to work out how much time you need to spend exposing your skin to the sun in order to get the vitamin D you need. A good rule of thumb is to get half the sun exposure it takes for your skin to turn pink to get your vitamin D and expose as much skin as possible.
It can get complicated
Specific recommendations are not easy! Skin types are different and depending on the day of year, place and time of day, recommendations vary. Let’s see how complicated it can get if we expose a quarter of our body to the sun:
- At noon in Miami, an individual with skin type III would probably need about 6 minutes of exposure to the sun to make 1,000 IU of vitamin D in summer and 15 minutes in winter.
- Someone with skin type V would probably need around 15 minutes in summer and 30 minutes in winter.
- At noon in Boston during summer, an individual with skin type III would probably need about 1 hour of exposure to the sun to make 1,000 IU of vitamin D.
- Someone with skin type V would probably need about 2 hours of exposure.
- During the winter months in Boston, it’s not possible for anyone to make vitamin D from the sun, no matter their skin type.
- And that’s assuming you’re exposing a quarter of your body. As you can see, there are lots of things that factor into vitamin D production. The best recommendation is to get half the sun exposure it takes for your skin to turn pink.
Other factors
There are other factors which can affect the amount of vitamin D your body makes from exposure to the sun. These are:
- The amount of skin you expose. The more skin you expose, the more vitamin D you can produce.
- How old you are. As you get older, your skin has a harder time producing vitamin D.
- Whether you’re wearing sunscreen. Sunscreen blocks a lot of vitamin D production.
- The altitude you’re at. The sun is more intense on top of a mountain than at the beach. This means you make more vitamin D the higher up you are (at higher altitudes).
- Whether it is cloudy. Less UVB reaches your skin on a cloudy day and your skin makes less vitamin D.
- Air pollution. Polluted air soaks up UVB or reflects it back into space. This means that if you live somewhere where there is lots of pollution, your skin makes less vitamin D.
- Being behind glass. Glass blocks all UVB, so you can’t make vitamin D if you’re in sunlight, but behind glass.
Indoor tanning
Your skin can also make vitamin D if you use an indoor tanning bed. As with natural sunlight, making the vitamin D you need from a tanning bed happens within minutes. You don’t need to tan your skin, or use a tanning bed for a long time to get the vitamin D you need.
If you choose to use a tanning bed, the Vitamin D Council recommends using the same common sense you use in getting sunlight. This includes:
Getting half the amount of exposure that it takes for your skin to turn pink.
Using low-pressure beds that has good amount of UVB light, rather than high-intensity UVA light.
Exposing your skin to UVB and the risk of skin cancer
Exposing your skin to the sun for too long, so that your skin starts to burn can be dangerous. This is because it can increase your risk of developing skin cancers. Research to date shows that moderate but frequent sun exposure is healthy but overexposure and intense exposure can increase your risk of skin cancer.
After you have exposed your skin for half the time it takes for you to turn pink, cover up with clothing and go into the shade. Using sunscreen is not as recommended as using shade and clothing to protect your skin, because it hasn’t consistently been shown to prevent all types of skin cancers. But if you do want to use sunscreen, use a sunscreen that blocks both UVA light and UVB light.
Protecting the skin
While covering up to prevent too much sun exposure is an important step in protecting yourself from skin cancer, research has not always shown that sunscreen is the safest and most effective method.
Research has shown that sunscreen helps prevent squamous cell carcinoma, but has no effect in preventing basal cell carcinoma. For melanoma, research has been contradictory.
Some research shows that sunscreen prevents melanoma, while other research shows that it increases your chance of getting melanoma.
For these reasons, the Vitamin D Council believes that covering up with clothing and/or going into the shade (after you get a little bit of sun exposure), is a safer way to protect yourself from too much sun exposure.
Infants have delicate skin which burns more easily, so it’s important to use extra care with your baby. This is why most doctors recommend giving your infant vitamin D supplement and not exposing your baby’s skin to the sun at all. See our pregnancy and breastfeeding page for more information on how to get the vitamin D your baby needs.
For older children, the advice is the same as for adults. You can expose your child’s skin for half the time it takes to burn in order to get the vitamin D they need. After that, make sure they cover up with clothes, shade and if you wish, sunscreen.
If you have had skin cancer or if you’re worried about exposing your skin to the sun, or that of your child, you can take vitamin D supplements instead.
Vitamin D supplements
In the 21st century, it’s hard to get daily full body sun exposure. On the days that you can’t get enough sun exposure, taking a supplement is an effective way to get the vitamin D your body needs. It‘s also a good way to get vitamin D if you’re worried about exposing your skin to the sun.
Women need for vitamin D
Different organizations recommend different daily intakes. Here are the recommendations from some organizations in the United States:
Recommended daily intakes from various organizations:
| Vitamin D Council | Endocrine Society | Food and Nutrition Board | |
| Infants | 1,000 IU/day | 400-1,000 IU/day | 400 IU/day |
| Children | 1,000 IU/day per | 1,000 IU/day per 25lbs of body weight | 600 IU/day |
| Adults | 5,000 IU/day | 1,500-2,000 IU/day | 600 IU/day, 800 IU/day for seniors |
The Food and Nutrition Board recommended daily intakes are the official recommendations by the United States government.
Why are the recommendations so different? Some researchers believe that there isn’t enough evidence to support taking higher amounts of vitamin D yet. On the other hand, some researchers believe that research is proving, or will prove, that taking lower amounts isn’t enough.
Can I take more than the recommended amounts?
Yes, you can, but attention and care is needed if you choose to take more supplement than in the recommendations above. Here are the safe maximums set by the same organizations:
Upper limits set by various organizations:
| Vitamin D Council | Endocrine Society | Food and Nutrition Board | |
| Infants | 2,000 IU/day | 2,000 IU/day | 1,000-1,500 IU/day |
| Children | 2,000 IU/day | 4,000 IU/day | 2,500-3,000 IU/day per 25lbs of body weight |
| Adults | 10,000 IU/day | 10,000 IU/day | 4,000 IU/day |
Vitamin D is fat-soluble, which means your body has a hard time getting rid of it if you take too much. The Vitamin D Council recommends taking no more than the upper limit, meaning do not take anymore than 10,000 IU/day for adults.
While these amounts seem like a lot, keep in mind that your body can produce 10,000 to 25,000 IUs of vitamin D after a little bit of full body sun exposure. Vitamin D toxicity, where vitamin D can be harmful, usually happens if you take 40,000 IU a day for a couple of months or longer.
In some diseases, researchers have studied the safety and benefits (if any) of these types of high doses of vitamin D. These diseases include multiple sclerosis and prostate cancer.
If you have a disease for which research has shown there may be a benefit in taking larger amounts of vitamin D, and you would like to consider taking more than 10,000 IU/day, the Vitamin D Council recommends taking the following precautions:
Work with your doctor
Test your vitamin D [25(OH)D] levels every 3 months and make sure that your blood levels are within the safe and healthy range.
Form of vitamin D should women should take and how should they take
The Vitamin D Council recommends taking vitamin D3 rather than vitamin D2. Vitamin D3 is the type of vitamin D your body produces in response to sun exposure, while vitamin D2 is not. In the United States, most over-the-counter vitamin D supplements are D3, but check to make sure. Vitamin D2 is sometimes prescribed by doctors because that is what pharmacies have available. If your doctor prescribes you D2, ask them if you can take vitamin D3 instead.
Vitamin D3 supplements aren’t vegetarian and some part of the production in making them occur outside the United States. If you have ethical concerns with taking vitamin D3, then sun exposure is a good option and vitamin D2 can be an alternative.
Other than that, it doesn’t matter what form of vitamin D you take, whether it’s in a capsule, tablet or liquid drop. For most people, vitamin D is easily absorbed in the body and you don’t need to worry about what time of day you take it or whether you take it with meals.
Cod liver oil contains vitamin D. However, the Vitamin D Council recommends against taking cod liver oil because of the high amount of vitamin A there is in cod liver oil compared to vitamin D. Vitamin A is also a fat-soluble vitamin, so your body has a hard time getting rid of it and too much vitamin A can be harmful.
Women having Trouble absorbing vitamin D supplements
Some people get tested for vitamin D and find, despite taking vitamin D regularly, that they’re still not getting enough vitamin D. This means your body is having a hard time absorbing your vitamin D supplements. The Vitamin D council recommends that if you’re having this problem, you can try these options:
- Take vitamin D under your tongue rather than swallowing it (subliminally).
- Try relying on more sun exposure.
- Increase your intake.
- Be sure to test your vitamin D [25(OH)D] levels to make sure your new regimen is safe and effective. The Vitamin D Council recommends testing every 3-6 months if you’re trying different regimens.
Vitamin D supplements women can take
Most people can take vitamin D supplements with no problems. However, care is needed in a few situations. These situations include:
If you’re taking certain other medicines: digoxin for an irregular heartbeat (atrial fibrillation) or thiazide diuretics such as hydrochlorothiazide or bendroflumethiazide (commonly used to treat high blood pressure). In this situation, don’t take high doses of vitamin D. You should also have your digoxin level monitored more closely if you’re taking vitamin D.
If you have one of these medical conditions: primary hyperparathyroidism, Hodgkin’s or non-Hodgkin’s lymphoma, a granulomatous disease, kidney stones, some types of kidney disease, liver disease or hormonal disease, you should get advice from a specialist. See our Hypersensitivity page for more information.
Don’t take vitamin D if you have high blood calcium levels, unless under the care of your physician.
You may need more than the usual dose of vitamin D if you’re taking certain medicines which interfere with vitamin D. These include: carbamazepine, phenytoin, primidone, barbiturates and some medicines used for the treatment of HIV infection.
Sun exposure and Vitamin D supplements
Yes. In fact, that is the Vitamin D Council’s recommendation. On days that you do not get enough full body sun exposure, it is important to take a supplement. For most people on the Monday-Friday indoor work schedule, that means taking a supplement 5-6 days a week and getting sun exposure on a day or two during the weekend.
Vitamin D from women diet
There are small amounts of vitamin D in a few foods, which makes it nearly impossible to get what you need from food. However, these foods include:
- Fatty fish
- Beef liver
- Egg yolks
- Fortified milk and orange juice
- Fortified cereals
- Infant formula
The Vitamin D Council believes that trying to get enough vitamin D from your diet is unlikely to give you the vitamin D you need.
Vitamin D is a star nutrient these days, as research links it to numerous health benefits. Studies suggest vitamin D may go beyond its well-established role in bone health and reduce the risk of cancer, heart disease, stroke, diabetes, autoimmune diseases, and more.
What makes vitamin D unique is that it is a vitamin and also a hormone your body can make from the sun. Despite the ability to get vitamin D from food and the sun, an estimated 40%-75% of people are deficient.
Why Vitamin D is not abundant in our food choices and the sun is not a reliable source for everyone.
Many factors affect the skin’s ability to produce vitamin D, including season, time of day, latitude, air pollution, cloud cover, sunscreen, body parts exposed, color, and age. Dermatologists recommend using sunscreen and getting vitamin D from food and supplements rather than risk the harmful rays of the sun.
Role of Vitamin D
Vitamin D is naturally present in few foods. Since 1930, virtually all cow’s milk in the U.S. has been voluntarily fortified with 100 IU of vitamin D per cup. Food manufacturers are fortifying other foods, such as yogurt, cereal, and orange juice, to help consumers fill the nutrient gap in their diets.
Ideally, vitamin D is added to a food or beverage that contains calcium. Vitamin D is needed for maximum absorption of calcium from the intestine, helping to build strong bones and teeth.
Together with calcium, vitamin D can help prevent osteoporosis in older adults. Without enough vitamin D, bones can become brittle and prone to fracture. It is estimated that more than 40 million adults in the U.S. have or are at risk of developing osteoporosis.
“Vitamin D deficiency is associated with low bone mass and osteoporosis, which is estimated to affect 10 million adults over the age of 50 in the U.S.,” says Atlanta rheumatologist Eduardo Baetti, MD. Even in Atlanta, where the sunshine is adequate all year long, Baetti says many of his patients — especially elderly and dark-skinned people — have low levels of vitamin D because the sun is not a reliable source.
Bone health was the single focus of the Institute of Medicine’s recommendations on how much vitamin D and calcium people should get. The recommendations for adults up to age 69 rose to 600 IU/day, and to 800 IU/day for adults starting at age 70. Older adults need more vitamin D because as they age, their skin does not produce vitamin D efficiently, they spend less time outdoors, and they tend to not get enough vitamin D.
Women Fitness hope the above source of information is able to quench the thirst of our readers about Vitamin D deficiency in women and how to overcome it.