If you feel tired, achy and flat this winter, low vitamin D symptoms may explain your condition. In fact, Statistics Canada found that about 40% of Canadians fell below the healthy vitamin D cut-off in winter, compared with 25% in the summer. More recently, the share of Canadians with very low levels, below 30 nmol/L, more than doubled in winter: 13% from November to March versus 5% from April to October. Here in Manitoba, the challenge grows even bigger. On the winter solstice, Winnipeg gets just 8 hours and 9 minutes of daylight, and the sun doesn’t rise until about 8:24 a.m. at the end of December. Fortunately, the right vitamin D foods and the best vitamin D supplement for your needs can close that gap.
This guide walks you through the low vitamin D symptoms to watch for, what is the right time to visit a doctor, which vitamin D foods you can keep in your kitchen, and how to choose the best vitamin D supplement at your local pharmacy.
Why Manitobans Run Low on Vitamin D Every Winter
Vitamin D is a nutrient your body can produce naturally. Your skin makes vitamin D when it is exposed to the sun’s UVB rays. However, The latitude of Winnipeg is 49° 53′ 4″ N. From roughly October to March, the sun stays so low in the sky that your skin makes little or no vitamin D, even on a bright, clear day. On top of that, short days mean most of us leave for work in the dark and come home in the dark. Meanwhile, our parkas, toques and mitts cover nearly every inch of skin.
Diet adds to the problem. Only a handful of foods naturally contain vitamin D, so most people fall short without fortified products or supplements. Indeed, researchers who studied Canadian Health Measures Survey data concluded that current food choices alone can’t keep most Canadians at healthy levels, especially in winter.
Other factors also lower your levels:
- conditions that block absorption, such as celiac disease, Crohn’s disease or bariatric surgery
- kidney or liver disease, since these organs help activate vitamin D
- higher body weight, because fat tissue holds on to vitamin D
- older age, since aging skin makes less of it
- certain medicines, including some seizure medications and long-term steroids
As a result, low vitamin D symptoms often creep in quietly between November and March.
Low Vitamin D Symptoms You Shouldn’t Ignore
Importantly, many people with low levels feel completely fine, at least at first. However, when symptoms appear, they tend to develop slowly and feel vague. In other words, low vitamin D symptoms overlap with many other conditions, from thyroid problems to anemia to the winter blues. For this reason, symptoms alone can’t confirm a deficiency.
Common Low Vitamin D Symptoms in Adults
- Fatigue and low energy that sleep doesn’t fix
- Bone pain or tenderness, often in the lower back, hips, legs or ribs
- Muscle aches, weakness or cramps, especially in the thighs and upper arms
- Low mood, particularly during the darker months
- Frequent colds or infections, although research on this correlation is mixed
- Slow wound healing
Severe Low Vitamin D Symptoms
When levels stay very low for a long time, the effects become more serious:
- Osteomalacia (soft bones) in adults: deep, aching bone pain, trouble climbing stairs and a waddling walk
- Falls and fractures, especially in older adults
- Rickets in children: bowed legs, delayed growth and late tooth development
- Tingling, muscle spasms or twitching, which can signal low calcium and need prompt medical care
Low Vitamin D Symptoms in Infants and Toddlers
- Low vitamin D can lower calcium levels and cause muscle spasms, twitching, breathing difficulties, or seizures.
- Babies may become irritable, fussy, sluggish, or less alert than usual.
- Vitamin D deficiency can slow growth and affect healthy bone and muscle development.
- Infants with low vitamin D may develop respiratory infections more often.
- Vitamin D deficiency can lead to muscle weakness and poor muscle tone.
Who Faces the Highest Risk?
Certain Manitobans face a higher risk than others. For example, people with darker skin need more sun exposure to make the same amount of vitamin D. One Canadian analysis found that 60.7% of people of colors in Canada who didn’t take supplements fell below the healthy cut-off in winter. Likewise, older adults, people who stay mostly indoors, those who cover their skin for cultural or religious reasons, and breastfed infants all run lower. Not surprisingly, people in these groups notice low vitamin D symptoms more often.
When Should You Get Checked for Low Vitamin D Symptoms?
In Manitoba, vitamin D blood testing follows specific rules. For example, Choosing Wisely Manitoba labs perform the 25-hydroxy vitamin D test – a laboratory procedure that measures the concentration of 25-hydroxyvitamin D in the blood- only for patients who meet set criteria. These criteria include:
- Metabolic bone disease (such as rickets, osteomalacia, or osteoporosis)
- Abnormal calcium, magnesium, or phosphate levels in the blood
- Parathyroid disease (such as hyperparathyroidism or hypoparathyroidism)
- Malabsorption syndromes (such as celiac disease or inflammatory bowel disease)
- Chronic renal (kidney) or liver disease
- Use of anticonvulsants (medications that affect vitamin D metabolism)
- Suspected hypervitaminosis D (toxicity caused by too much vitamin D)
Even the Diagnostic Services Manitoba lab at the Health Sciences Centre also runs the 25-hydroxyvitamin D blood test for people meeting specific medically indicated criteria. Therefore as a result, healthy people don’t get routine screening for low vitamin D symptoms.
So, talk to your family doctor or nurse practitioner about testing if you:
- have persistent low vitamin D symptoms, especially bone pain or muscle weakness
- live with osteoporosis or have had a fracture from a minor fall
- have celiac disease, Crohn’s disease or another absorption problem, or have had bariatric surgery
- have kidney or liver disease
- take medications that affect vitamin D, such as anticonvulsants (anti-seizure drugs)
- already take a high prescribed dose and need monitoring
- Have calcium, magnesium, or phosphate deficiency
If you do get tested, here’s how to read the result. A level below 30 nmol/L points to a risk of deficiency and poorer bone health, while a level above 50 nmol/L supports bone health in practically everyone. Even without a test, your provider may simply recommend a standard daily supplement, since that approach works safely for most people.
Vitamin D Foods to Stock in Your Manitoba Kitchen
Fortunately, eating well makes a measurable difference. Statistics Canada found that adults who ate fish at least once a week were less likely to have very low levels than those who ate no fish (6% versus 11%). Similarly, drinking one glass of milk a day lowered the rate from 10% to 6%.
Natural Vitamin D Foods
- Fatty fish: salmon, rainbow trout, mackerel, herring and sardines lead the list. Notably, canned salmon with the bones also adds calcium.
- Egg yolks: each yolk adds a small amount, so eggs help as part of a mix.
- Cod liver oil: one of the richest natural sources, but take care, because it also contains vitamin A.
- UV-exposed mushrooms: some grocers now sell mushrooms treated with UV light, which boosts their vitamin D.
Fortified Vitamin D Foods
As of January 1, 2026, Health Canada passed a law to increase the amount of vitamin D in milk, margarine and fortified plant-based beverages doubled. Now, a 250 mL serving of cow’s milk or 100 mL of plain yogurt provides about 200 IU, and a serving of kefir offers about 100 IU. Plus, plant-based beverages labelled “fortified”, contain the same vitamin D level as cow’s milk. Margarine also carries mandatory vitamin D fortification.
Taken together, these vitamin D foods give you a solid base.
Easy Ways to Add Vitamin D Foods to Your Day
- First, cook your morning oatmeal in milk or a fortified plant-based beverage instead of water.
- Next, swap your usual coffee for a latte.
- Then, plan a weekly mackerel, salmon or trout dinner.
- Also, try sardines or canned salmon on whole-grain toast for a quick lunch.
- Finally, finish the day with a yogurt or kefir snack.
Still, vitamin D foods rarely cover your full needs in a Manitoba winter. That’s where supplements come in.
Choosing the Best Vitamin D Supplement in Canada
First, know your targets. Health Canada recommends 600 IU a day for adults aged 18 to 70 and 800 IU a day for those over 70. In addition, Health Canada advises everyone over 50 to take a 400 IU daily supplement, since few foods contain vitamin D. Meanwhile, the Tolerable Upper Intake Level sits at 4,000 IU per day. In Canada, you can buy vitamin D products without a prescription when they contain up to 2,500 IU per dose.
D3 or D2: Which Makes the Best Vitamin D Supplement?
Generally, doctors prefer vitamin D3 (cholecalciferol), because it raises blood levels more effectively than vitamin D2 (ergocalciferol). Vegans can choose plant-based D3 made from lichen.
Types of Vitamin D Available Over the Counter
Pharmacies stock tablets, softgels, chewables and liquid drops. Drops work especially well for children and for anyone who dislikes swallowing pills. For example, many infant drops deliver 400 IU per drop, while some adult drops deliver 1,000 IU per drop.
What to Check on the Label
- An NPN or DIN, which shows Health Canada authorized the product
- Vitamin D3 as the active ingredient
- The dose in IU and micrograms (40 IU equals 1 microgram)
- A sensible dose, rather than a mega-dose that tops the upper limit
Additionally, eat your vitamin D supplement with a meal. Your body absorbs more vitamin D when you eat it with healthy fats than when you take it on an empty stomach.
What Doctors Typically Prescribe
Doctors typically tailor the dose to each patient. Generally, we suggest that healthy adults take a daily D3 supplement from fall through spring. Most adults over 50 should take at least the 400 IU Health Canada recommends, and many people choose 1,000 IU. For a confirmed deficiency, we may prescribe a higher dose for a few months, then step down to a maintenance dose and recheck when appropriate.Overall, choose the best vitamin D supplement by matching it to your blood vitamin D levels, health history, and daily routine, and by selecting one you’ll remember to take consistently.
Safety: Can You Take Too Much?
No. You should always avoid excess dosage of Vitamin D. Because your body stores vitamin D in fat tissue, excess doses can build up to harmful levels. Exceeding the upper limit may cause high blood calcium and kidney damage. Warning signs include nausea, vomiting, extreme thirst, frequent urination and confusion. Additionally, people with kidney stones, sarcoidosis or parathyroid problems should check with a doctor before they start. In short, even the best vitamin D supplement can cause harm at extreme doses.
Frequently Asked Questions
No. Tanning beds raise your risk of skin cancer, and Canadian health experts advise against them. Instead, rely on food and supplements.
Typically, blood levels climb over two to three months of steady supplementation. Many people notice less fatigue and muscle aching within a few weeks to a few months.
Usually, liquid drops work best for infants and young children. Health Canada recommends a daily 400 IU supplement for breastfed babies. As always, check the dose for your child’s age with your pharmacist or doctor.
Sometimes, but rarely in a Manitoba winter. Most people need a supplement from October through March.
That said, prevention costs very little. Here are my key takeaways:
–Assume you’ll run low in winter. At our latitude, your skin makes little vitamin D from October to March.
–Eat for vitamin D every day. Fish, eggs and the newly boosted fortified dairy and plant beverages make vitamin D foods easier than ever to fit into your meals.
–Pick a sensible supplement. For most adults, the best vitamin D supplement means a daily D3 tablet or drop at a moderate dose, taken with a meal.
–Don’t chase mega-doses. More isn’t better, and very high doses can harm your kidneys.
–Speak up about persistent symptoms. If low vitamin D symptoms continue despite good habits, ask your provider whether you meet Manitoba’s testing criteria.
Estimated reading time: 11 minutes
Key Takeaways
- Low vitamin D symptoms affect many Canadians in winter, with Manitoba facing the greatest challenge due to limited sunlight.
- Common low vitamin D symptoms include fatigue, bone pain, muscle weakness, and low mood, but many feel fine initially.
- Infants and toddlers can experience low vitamin D symptoms like muscle spasms and slow growth, requiring attention.
- Certain groups, such as older adults and those with darker skin, are at higher risk of deficiency and noticing symptoms.
- Diet and supplements play a crucial role in preventing low vitamin D symptoms, especially during the winter months.
