Vegans, Beware: Micronutrient Deficiency Risks You Need To Know

A vegan diet can be deficient in several micronutrients, including vitamin B12, vitamin D, calcium, iron, and zinc.

Vitamin B12 is found predominantly in animal products, and a deficiency can cause megaloblastic anemia, which involves the bone marrow producing oversized, undeveloped red blood cells, leading to low red blood cell levels.

Omega-3 fatty acids are also lacking in vegan diets, which can affect the skin, causing swollen, itchy rashes or scaly, dry patches.

Iodine is another nutrient that is lacking in vegan diets, and a deficiency can lead to hypothyroidism, which is characterised by an inability to tolerate colder temperatures.

Iron is also more difficult to absorb from plant-based sources, and a deficiency can cause anemia, which restricts oxygen delivery to cells around the body.

Finally, creatine, which is found in animal tissues, is typically lower in vegan diets.

Vitamin B12

The recommended daily allowance (RDA) of B12 depends on a person's age:

• Adults and teenagers: 2.4 micrograms (mcg) per day
• Children between 9 and 13 years old: 1.8 mcg per day
• Children between 4 and 8 years old: 1.2 mcg per day
• Toddlers between 1 and 3 years old: 0.9 mcg per day
• Infants between 7 and 12 months old require 0.5 mcg of B12 per day, and babies less than 6 months old only need 0.4 mcg per day
• Pregnant women require 2.6 mcg, while breastfeeding women need 2.8 mcg per day

Vegans can obtain vitamin B12 from fortified foods such as fortified plant-based milk, fortified cereals, and nutritional yeast. They can also take vitamin B12 supplements.

The British Dietetic Association (BDA) advises that those following a vegan diet should use Good Manufacturing Practice (GMP)-certified vitamin B12 supplements and consume B12-fortified foods.

Symptoms of B12 Deficiency

A vitamin B12 deficiency can cause:

• Anaemia
• Nervous system damage
• Reduced growth and healing
• Weakness and fatigue
• Tingling in the hands and feet
• Problems with the digestive system
• A sore tongue or mouth ulcers
• Feeling faint or dizzy
• A decline in memory, judgement, and understanding
• Tinnitus (ringing, buzzing, or hissing sounds in the ears)

Iodine

The iodine content of a particular plant food varies depending on how much iodine was present in its growing environment. There is no easy way of knowing how much iodine is in plant foods, but they may contain low amounts. It is therefore recommended that vegans top up their iodine intake to avoid iodine deficiency.

The iodine status of vegans tends to be lower than for other diet groups and for what is considered healthy. These lower iodine concentrations haven’t been correlated with thyroid problems among vegans. Nonetheless, it’s prudent for vegans to meet iodine recommendations.

• Rare Vegan Iodine Sources: Many of the best sources of iodine come from animal-based products, like fish, eggs, and cow's milk.
• Iodine Absorption Antagonists: Iodine is not always readily absorbed by the body, especially for people that consume known iodine antagonist foods that slow iodine's absorption further and counteract its beneficial effects. The dilemma for vegans is that many of the iodine antagonists are vegan staples - flaxseeds, soy, and raw cruciferous veggies like broccoli, cauliflower, or cabbage all negatively affect your iodine levels.

Vegan Dietary Sources: Best Iodine-Rich Foods

• Dried Sea Vegetables: Dulse, Kelp, Nori, & More! One liter of ocean water contains 50 mcg of iodine, and dried sea vegetables benefit from this essential mineral. With 40 to 60 mcg in a single dried sheet, the dosage is relatively high, so watch your portions closely to avoid overeating iodine.
• Fruit Plants High in Iodine: Strawberries, Prunes, & Cranberries. A few of our favorite fruits also happen to be vegan foods high in iodine, along with a load of other essential vitamins and minerals.
• Vegetables High in Iodine Green Beans, Corn, & Potatoes. Vegetables are moderate sources of iodine in a vegan diet that won't massively pump up your intake but still offer a little boost.
• Leafy Greens: Spring Greens & Watercress. Leafy greens offer some extra iodine for vegans that probably eat a decent amount of these veggies already.
• Iodized Salt. Iodized salt can be used to meet iodine recommendations.

Calcium

• Dark, green, leafy vegetables, such as spinach, turnip, mustard, and collard greens.
• Calcium-fortified plant milk and yoghurt alternatives.
• Calcium-set tofu, made with calcium sulfate.

Iron

It is important to note that tea, coffee, and phytates can reduce iron absorption. Vitamin C, on the other hand, can increase iron absorption.

The recommended daily intake of iron varies depending on age and sex. In the UK, the recommended daily intake for non-menstruating people is 11.3 mg, and for menstruating people, it is 14.8 mg. For non-menstruating people over the age of 50, the recommended daily intake is 8.7 mg, and for menstruating people over 50, it is 14.8 mg.

Zinc

Phytates, which are commonly found in plant foods, reduce zinc absorption, and some researchers suggest that this increases the zinc needs of vegetarians by up to 50%. Vegans should be aware of their zinc intakes and monitor for deficiency symptoms.

Frequently asked questions