The three most common vitamin and mineral deficiencies worldwide are iron, vitamin A, and iodine, significantly impacting global health, especially in children and pregnant women, leading to issues like anemia, impaired growth, and cognitive problems; other widespread deficiencies include zinc, folate, vitamin D, and vitamin B12.
Micronutrient deficiencies, especially iron, vitamin A, zinc, iodine, and folate, are prevalent in the developing world, affecting an estimated 2 billion people worldwide. They are a major contributor to infections and associated with severe illness and death (16).
B1 (Thiamine): Essential for energy production, nervous system health, and muscle function. B2 (Riboflavin): Promotes skin health, supports iron absorption, and contributes to growth. B3 (Niacin): Aids in energy production and cholesterol regulation.
Niacin deficiency is associated with malnutrition and causes symptoms involving the skin as well as the digestive and nervous systems. Sun exposure with a severe vitamin B3 deficiency may trigger a thick and scaly, dark-pigmented rash, known as pellagra.
Deficiencies in iron, vitamin A and iodine are the most common around the world, particularly in children and pregnant women.
Vitamin D is used by your body for energy, to support a healthy immune system, and build healthy bones. The body's best source of Vitamin D is produced when your skin is exposed to sunlight, which can be a tricky thing to accomplish at certain times of the year, depending on where you live.
A vitamin deficiency test, or nutrients test, assesses vitamin or mineral levels in the blood. Either finger-prick blood tests or venous blood tests are available to collect blood. You can perform a finger-prick test on your own using a lancet to prick your finger so you can collect blood.
Cutaneous manifestations associated with vitamin B12 deficiency are skin hyperpigmentation, vitiligo, angular stomatitis, and hair changes. A diagnosis of vitamin B12 deficiency is often overlooked in its early stages because these signs are not specific to vitamin B12 deficiency alone.
Skin issues: A lack of vitamin A can cause dry, scaly and/or itchy skin. Infertility: Vitamin A plays an important role in your reproductive system. Vitamin A deficiency can lead to trouble conceiving and infertility. Growth issues: Vitamin A deficiency can cause delayed growth and development in children.
Medically reviewed by Carmen Pope, BPharm. Last updated on Feb 26, 2025. Generally, it takes a few weeks of taking daily vitamin D supplements for vitamin D levels in the body to rise. Each 1,000 IU of vitamin D3 taken daily is expected to raise blood levels of 25(OH)D by 10 ng/ml after a few weeks.
Two large eggs provide a significant portion of your daily Vitamin B12, roughly 1.4 to 2.7 micrograms, depending on size, with almost all of it found in the yolk, contributing around 15-46% of the Daily Value (DV) for adults, making eggs a good source of this essential nutrient for red blood cell formation and nerve function, though absorption from eggs might be lower than meat, notes Healthline, EggInfo, and Australian Eggs.
For vitamins and minerals, these should not be taken together:
The foods highest in Vitamin B12 are animal products, with clams and liver (beef, lamb) being exceptionally rich sources, often providing several hundred percent of the daily value in a single serving, alongside seafood like mussels, sardines, and salmon, dairy, eggs, and fortified cereals and nutritional yeast for vegans.
B12 deficiency can trigger specific food cravings, most notably for meat, fish, or eggs, as the body seeks animal-based sources to replenish the vitamin, especially in those on vegetarian/vegan diets or older adults. While cravings for sugary or salty foods can also signal general B-vitamin issues, the distinct urge for protein-rich animal products is a key indicator, but professional testing is crucial for confirmation.
Iron, folate, zinc, iodine, and vitamin A are among the most occurring micronutrient deficiencies in the world, and all of these contribute to intellectual impairment, poor growth, perinatal complications, and higher morbidity and mortality [1].
People need vitamin B-12 for the brain to work well. If not treated, vitamin B-12 deficiency can lead to issues with the nerves, brain or spinal cord. These might include lasting tingling in the hands and feet or trouble with balance.
The observed reduction in pruritus severity in our meta-analysis may be attributable to these anti-inflammatory effects, suggesting that vitamin D could be particularly beneficial for patients with inflammatory skin conditions.
Here are 10 unexpected signs of a vitamin D deficiency that may surprise you.
Vitamin deficiencies: Deficiencies in certain vitamins such as B12 and D may lead to problems with the joints, including crepitus or popping joints. A calcium deficiency can also cause cracking bones. Poor calcium intake can lead to decreased bone density. This could make your joints more likely to pop.
Vitamin B12deficiency symptoms may include:
The Boots Vitamin B12 Blood Test Kit checks your vitamin B12 levels, using a finger-prick blood sample. Use of this kit requires internet access. All personal data in relation to this product, services and online platforms are collected and processed by MyHealthChecked.
Numerous studies have found an association between vitamin deficiency and thyroid disorders (TD). The presence of anti-parietal cell antibodies is indicative of reduced ability to absorb vitamin B12.
Fatigue and weakness
Chronic fatigue is one of the most common and overlooked signs of vitamin deficiency. If you find yourself constantly tired, even after a good night's sleep, a lack of vitamin B12 might be to blame.
The Welzo Home Health Test for Vitamin Deficiency offers a simple and convenient way to check your vitamin levels at home. This test screens for key vitamins like D, B12, and folate, which are essential for energy, immune function, bone health, and mental clarity.
Any currently treated or untreated nutrient deficiency or disease. These include, but are not limited to, Protein Energy Malnutrition, Scurvy, Rickets, Beriberi, Hypocalcemia, Osteomalacia, Vitamin K Deficiency, Pellagra, Xerophthalmia, and Iron Deficiency.