What Nutrients are Lacking in Your Stay-home Diet?

What Nutrients are Lacking in Your Stay-home Diet?

Contributed by Eve Persak, Nutrition Advisor, MS RD CNSC CSSD

What Nutrients are Lacking in Your Stay-home Diet?

As we all adjust to largely living our lives at home, our diets have likely required adjustments as well.

Certain favourites or household staples may not be readily available at the supermarket. Likewise, we may rely more heavily on pantry or frozen foods to reduce trips to the grocery store. Our personal culinary skills – or lack thereof – and the available kitchen equipment may dictate the recipes we attempt. Because of that, takeouts or deliveries become especially appealing – or even necessary.

Over time, even small changes in our daily food choices can have genuine - and sometimes noticeable - effects on our overall nutrition.

Is our ‘new’ diet inadequate in any way? Perhaps so. Full-blown deficiencies aren’t common, but there are a handful of nutrients that may be lacking under our current extended and extenuating stay-home circumstances.

Fortunately, by taking more of certain foods and adjusting food preparation, you can step up and keep up your intake, if and as needed. As always, try to eat fresh and obtain nutrition from food first. If need be, consult a trusted health professional for support with supplementation.


This vitamin is essential for immune function and the growth, development and repair of all body tissues. Unfortunately, of all of the micronutrients, vitamin C is the most fragile. It degrades quickly over time, with changes in temperature and exposure to open air.

As such, foods rich in vitamin C – like fruits and vegetables – are best consumed with as little delay and manipulation from the point of picking as possible. To be fair, under usual circumstances, much of our produce is shipped from elsewhere and vitamin C losses naturally occur with processing, shipping, and storage (both at the market and in our own homes).

However, the reduced availability of fresh, plant-based foods presents an added challenge. We may rely on alternative, processed forms – like dried, canned or frozen foods. When dried or dehydrated, fruits can lose up to 80 per cent of their vitamin C content. When cooked in water and drained - as with blanching before canning - up to 75 per cent may be lost. Similarly, cooking and reheating can cause a reduction of another 50 per cent during the process.

So, what can you do to ensure that you’ve met your daily vitamin C needs? Seek out produce with a robust vitamin C content. This includes fruits such as guava, kiwis, strawberries, oranges, papaya and tomatoes, as well as vegetables like bell peppers, broccoli and snow peas.

Buy fresh whenever you can. After purchase, store fruits and vegetables in the refrigerator rather than on the kitchen countertop. Likewise, wash and slice just before eating, instead of prepping in advance.

With fruits, consider frozen. Frozen vegetables are dipped in hot water before freezing – thereby reducing available vitamin C - but fruits are flash frozen, which locks in their vitamin C content at the peak of their ripeness.


While not as delicate as vitamin C, B vitamins are also prone to degradation. Water-soluble, they tend to be more sensitive to heat. Likewise, B vitamins are lost when food choices are processed. Therefore, simply keeping your food choices as ‘whole’ as possible – for example by choosing whole grains over refined ones - can be a huge help.

Of the family of B vitamins, the two that are especially sensitive are folate (B9) and thiamin (B1).

Folate plays a critical role in DNA synthesis, cell growth and repair, heart health, and developing and maintaining the brain and nervous system.

Of the B family of vitamins, folate is most sensitive – with 50 per cent loss from drying, and another 70 per cent loss from water-based cooking and draining.

To maintain adequate levels of folate, add folate-rich foods to your shopping list. Fresh sources include asparagus, edamame, spinach, broccoli, avocados, mangoes, lettuce, oranges, Brussels sprouts and snap peas.

Keep lentils and whole grains in the pantry. Many countries fortify grain products – like breads, breakfast cereals, noodles and flours - with folic acid, which can also give folate levels a boost. While taking supplements can help, it’s important to be careful with this option. Many individuals have genetic predispositions, which alter the way their systems metabolise folate.

While not as delicate as folate, thiamin (vitamin B1) is a close runner-up. This micronutrient is crucial for metabolism, as well as muscle contraction and nerve communication. Drying foods with this vitamin can result in approximately 30 per cent loss, while cooking and draining causes 70 per cent loss, and reheating reduces thiamin content by 40 per cent. Focusing on foods that offer ample vitamin B1 can help you cover your bases. These include nuts, seeds, peas, beans, brown rice, squash, asparagus, oats, oranges, eggs and tofu. As with folate, some grain products – such as rice, pasta, breads and cereals - are fortified with thiamine, as well.

Changes in our food choices can decrease the amount of vitamin D available to the body.

However, at present, any dip in our bodies’ vitamin D levels is more likely due to reduced exposure to the sun. With our at-home and largely indoors restrictions, we’re absorbing less of this nutrient from sunlight via the skin – which for most people, is usually more than enough to meet daily vitamin D needs.

Why does this matter? Vitamin D is most often associated with mineral absorption and bone integrity, but it’s also valuable for sleep, immunity and inflammation control – which are especially important during the pandemic. Vitamin D isn’t as prolific in the natural foods as other vitamins. Cold water, fatty fish such as tuna, salmon, mackerel – are the richest sources. Egg yolks, cheese and beef liver offer small amounts, too. Plant-based sources are limited to mushrooms – which provide variable quantities, but most when sun-dried. Fortified foods – such as dairy products, plant-based dairy alternatives and juices can serve as a useful support as well.


On the whole, minerals are much more resistant to cooking or processing losses than vitamins. However, one mineral that may require a bit of attention is potassium.

Potassium is essential for muscle contraction, metabolism and fluid management, which affects cardiac function and blood pressure. While deficiencies are rare, many studies suggest that people aren’t meeting the amounts recommended for good health. Potassium serves as one of our main electrolytes, alongside sodium. When levels of one rise, the other must also rise to match it, to maintain a balanced concentration within the bloodstream. This delicate interplay ensures safe and optimal fluid levels in the body.

Potassium is somewhat sensitive to processing. Cooking can lead to 30 per cent loss, and cooking and draining can reduce amounts by 70 per cent. Yet the larger issue is the increase in sodium that our stay-home diets may present. Increased reliance on more shelf-stable, processed foods may boost our daily sodium intake as food manufacturers use salts as preservatives and flavour enhancers. Takeaway and delivery foods are often loaded with salts to bring out flavours. On its own, potassium intake might not be as robust as previously. However, this may be more relevant when viewed in tandem with the excess salt that may have crept into our meals and snacks of late.

What can we do? Opting for fresh or frozen produce – over canned items – can side-step losses. Also, choosing to steam, roast or lightly sauté can keep potassium levels more intact than boiling and discarding the water.

Thankfully, potassium-rich foods can easily be found. Fruits, vegetables, legumes and grains are great sources. Those with the highest amounts include bananas, melons, apricots, avocados, spinach, broccoli, white and sweet potatoes (baked, not boiled), quinoa, coconut water, peas and cucumbers. While many supplements exist on the market, it is not considered safe to supplement with potassium unless under close guidance of a medical professional. Taking the wrong amount can have serious, even life-threatening effects.