Understanding Hair Follicles and Hair Growth

The Basics of Hair Follicles

Did you know that there are approximately 100,000 hair follicles on your head? Each hair follicle undergoes four distinct phases: anagen (growth), catagen (transition), telogen (resting), and exogen (shedding). On average, individuals shed between 50 to 100 hairs daily, primarily during the exogen phase of hair growth.

The Role of Vitamins in Hair Care

Vitamins play a crucial role in maintaining healthy hair and promoting growth. Among these, vitamin B12 is often discussed for its potential benefits. While some research has linked deficiencies in B-vitamin complexes to hair loss, the studies conducted have been limited in scope and have produced inconclusive results.

The B Vitamins and Their Sources

Overview of B Vitamins

There are eight essential B vitamins that contribute to overall health:

– B1 (thiamin)
– B2 (riboflavin)
– B3 (niacin)
– B5 (pantothenic acid)
– B6 (pyridoxine)
– B7 (biotin)
– B9 (folate)
– B12 (cobalamin)

Dietary Sources of B Vitamins

B vitamins can be found in a variety of foods, including:

– Whole grains
– Dark, leafy vegetables
– Meats
– Fish
– Whole eggs
– Beans and legumes
– Nuts
– Avocados

Vitamin B12, in particular, is primarily obtained from animal products such as:

– Fish and shellfish
– Liver
– Red meat
– Eggs
– Poultry
– Dairy products (milk, cheese, yogurt)
– Fortified nutritional yeast
– Fortified breakfast cereals
– Enriched soy or rice milk

The Importance of Vitamin B12

Functions of Vitamin B12

Vitamin B12 is essential for several bodily functions, including DNA synthesis, neurological functions, and the formation of red blood cells. These red blood cells are critical for hair growth, as they deliver oxygen to the follicle cells.

Impact on Hair Growth

During the anagen (growth) phase, hair follicle cells can remain active for three to five years or longer. At any given time, approximately 90% of hair follicles, or about 90,000, are in this growth phase. Adequate levels of vitamin B12 and other B vitamins may promote proper hair growth and help reduce the risk of premature hair loss.

While there is some evidence suggesting that deficiencies in various B vitamins may be linked to hair loss, the research specific to vitamin B12 remains limited and the findings are not definitive. The potential advantages of vitamin B12 for hair health largely stem from its vital role in DNA synthesis and red blood cell production.

References

1) Almohanna HM, Ahmed AA, Tsatalis JP, and Tosti A. (2019) ‘The Role of Vitamins and Minerals in Hair Loss: A Review’ Dermatology and Therapy (9):51-70 https://doi.org/10.1007/s13555-018-0278-6
2) Roland, J. ‘What are the Four Stages of Hair Growth?’ https://www.healthline.com/health/stages-of-hair-growth Accessed February 11, 2022
3) Ashpari, Z. ‘Can I use vitamins to promote hair growth?’ https://www.medicalnewstoday.com/articles/318403 Accessed February 11, 2022
4) Harvard TH, Chan School of Public Health. ‘Vitamin B12’ The Nutrition Source https://www.hsph.harvard.edu/nutritionsource/vitamin-b12 Accessed February 12, 2022